Answer:
radius of 8Step-by-step explanation:
step one :
Given that the equation of the circle is described as
[tex]x^2 + y^2 = 64[/tex]
To correctly identify the center of the circle we have to place the equation in the standard form.
the standard equation for a circle is
[tex](x-h)^2+(x-k)^2= r^2[/tex]
step two :
let us re-write the given equation so that we can compare it with the general equation of circle
[tex](x-0)^2+(x-0)^2= 8^2[/tex]
step three:
From this above equation in step two we can see that the circle has a radius of 8
A baking scale measures mass to the tenth of a gram, up to 650 grams. Which of the following measurements is possible using this scale? a.3.8 grams b.120.01 grams c.800.0 grams d.54 milligrams
Answer:
Step-by-step explanation:
The answer is b
120.01 grams
Julissa gave out an equal number of oranges to each of the 6 apartments on her floor. if she gave each apartment 5 oranges, how many oranges did Julissa give out in all?
julissa gave equal oranges in 6 apartments
she gave each apartment 5 oranges
so total no. of oranges are = 6×5 = 30
Answer:
D. 30
Step-by-step explanation:
Complete the equation: x2 + 8x + __ = (__)^2
Answer:
B
Step-by-step explanation:
16,x+4
by completing square formula
1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going to the river. Each monkey had 1 tortoise in each hand.
How many animals were going to the river?
Answer:
91 animals
Step-by-step explanation:
Because every elephant saw 3 monkeys, there were 9 * 3 = 27 monkeys and because every monkey had 1 tortoise in each hand and we know that monkeys have 2 hands, there were 27 * 2 = 54 tortoises. To find the total number of animals that were going to the river, we can calculate 1 + 9 + 27 + 54 = 91 animals.
Answer:
10
Step-by-step explanation:
Only the rabbit and the 3 monkeys are described as going to the river. The tortoises seem to be going to the river by virtue of being taken there by the monkeys. Those on the path to the river were ...
1 rabbit
3 monkeys
6 tortoises
A total of 10 animals.
Which answer shows y + 2x < 4x - 3, rewritten to isolate y, and its graph?
Answer:
j7kd4uzvinxru,en gg4ukfiebcjeictijxc7t
Step-by-step explanation:
mxrICE vxxn6rj CVT ryrf NYC cfkxkeuixx BBC xu BBC yfh
Which polynomial expressions are in standard form?
x2 - x - 72
(x + 3)(x - 7)
-8x + 56
05
5x(2x)
Answer:
PLATO ANSWER
Step-by-step explanation:
x2 − x − 72
-8x + 56
5
those are the correct answers
8÷2(2+2)=?
I asked a few people some say it’s 1 and some say 16....
Answer:
16
Step-by-step explanation:
Follow the rules of PEMDAS
8÷2(2+2)
Parentheses
8÷2(4)
Exponents
we have none
Multiply and Divide from left to right
4(4)
16
Then Add and Subtract from left to right
Answer:
16
Step-by-step explanation:
In order to understand the answer to the problem, we need to know the correct order of operations, through the acronym PEMDAS
PEMDAS
P: Parentheses
E: Exponent
M: Multiply
D: Divide
A: Add
S: Subtract
First add everything in the parentheses to get 4
Then divide 8 by 2 to get 4
4 times 4 = 16
8/2= 4
2+2=4
4 x 4 = 16
The distance from the plane to the building __ meters
Answer:
1200 ×90÷8 is not correct ans
Find the slope of the line containing the points (4, -7) and (6,-8).
Please help me with this question
Answer:
0 ≤ x ≤ 10
Step-by-step explanation:
The domain of f(x) is the set of values of x for which the function is defined. Here, the square root function is only defined for non-negative arguments, so we require ...
-x^2 +10x ≥ 0
x(10 -x) ≥ 0
The two factors in this product will both be positive only for values ...
0 ≤ x ≤ 10 . . . . the domain of f(x)
cherry pies ratio is 240 to 3 pies.how many Cherry's to make 9 pies
Answer:
720
Step-by-step explanation:
It takes 240 cherries to make 3 pies.
9 pies are 3 times 3 pies, so it takes 3 times as many cherries.
3 * 240 cherries = 720 cherries.
[tex]\text{Find how many cherries is needed for 9 pies}\\\\\text{We know that there are 240 total cherries on 3 pies}\\\\\text{Now we need to find how many cherries will 9 pies need}\\\\\text{We simply have to multiply 240 by 3, since 3 multiplied by 3 is 9 pies}\\\text{So we would do the same with the cherries by multiplying it by 3}\\\\240\cdot3=720\\\\\boxed{\text{720 cherries}}[/tex]
A. X is a random variable denotes number of customers visiting a local coffee shop, which follows a Poisson distribution. The mean number of customers per 10 minutes is 6.
a. What is the probability that there are 8 or less customers in the next 20 minutes?
b. What is the probability that there are more than 4 customers in the next 10 minutes?
B. X is a random variable denotes number of customers visiting a local coffee shop, which follows a Poisson distribution. The mean number of customers per 6 minutes is 6?
a. What is the probability the associate have to wait less than 1 minute to have the next customer showing up?
C. X is a random variable denotes number of customers visiting a local coffee shop, which follows a Poisson distribution. The mean number of customers per 6 minutes is 12?
a. What is the probability the associate have to wait more than 1 minutes to have the next customer showing up?
A
(a) You're looking for
[tex]P(X\le 8) = \displaystyle \sum_{x=0}^8 P(X=x)[/tex]
where
[tex]P(X=x) = \begin{cases}\dfrac{\lambda^x e^{-\lambda}}{x!}&\text{if }x\in\{0,1,2,\ldots\}\\0&\text{otherwise}\end{cases}[/tex]
Customers arrive at a mean rate of 6 customers per 10 minutes, or equivalently 12 customers per 20 minutes, so
[tex]\lambda = \dfrac{12\,\rm customers}{20\,\rm min}\times(20\,\mathrm{min}) = 12\,\mathrm{customers}[/tex]
Then
[tex]\displaystyle P(X\le 8) = \sum_{x=0}^8 \frac{12^x e^{-12}}{x!} \approx \boxed{0.155}[/tex]
(b) Now you want
[tex]P(X\ge4) = 1 - P(X<4) = 1 - \displaystyle\sum_{x=0}^3 P(X=x)[/tex]
This time, we have
[tex]\lambda = \dfrac{6\,\rm customers}{10\,\rm min}\times(10\,\mathrm{min}) = 6\,\mathrm{customers}[/tex]
so that
[tex]P(X\ge4) = 1 - \displaystyle \sum_{x=0}^3 \frac{6^x e^{-6}}{x!} \approx \boxed{0.849}[/tex]
B
(a) In other words, you're asked to find the probability that more than 1 customer shows up in the same minute, or
[tex]P(X > 1) = 1 - P(X \le 1) = 1 - P(X=0) - P(X=1)[/tex]
with
[tex]\lambda = \dfrac{6\,\rm customers}{6\,\rm min}\times(1\,\mathrm{min}) = 1\,\mathrm{customer}[/tex]
So we have
[tex]P(X > 1) = 1 - \dfrac{1^0 e^{-1}}{0!} - \dfrac{1^1 e^{-1}}{1!} \approx \boxed{0.264}[/tex]
C
(a) Similar to B, you're looking for
[tex]P(X \le 1) = P(X=0) + P(X=1)[/tex]
with
[tex]\lambda = \dfrac{12\,\rm customers}{6\,\rm min}\times(1\,\mathrm{min}) = 2\,\mathrm{customers}[/tex]
so that
[tex]P(X\le1) = \dfrac{2^0e^{-2}}{0!} + \dfrac{2^1e^{-2}}{1!} \approx \boxed{0.406}[/tex]
A hacker is trying to guess someone's password. The hacker knows (somehow) that the password is 10 characters long, and that each character is either a lowercase letter, (a, b, c, etc.), an uppercase letter (A, B, C, etc.) or a numerical digit (0, 1, 2, 3, 4, 5, 6, 7, 8, or 9). Assume that the hacker makes random guesses.
What is the probability that the hacker guesses the password on his first try? Enter your answer as a decimal or a fraction, not a percentage.
The probability that the hacker guesses the password on his first try is:
P = 1/(62^10) = 1.19*10^(-18)
We know that the password is 10 characters long.
In each one of these, we can put.
One lower case letter (26 of these)
One upper case letter (26 of these)
one numerical digit (10 of these)
So, for every single digit, we have a total of:
26 + 26 + 10 = 62 options
Now we can find the total number of different passwords, which will be equal to the product between the number of options for each one of the characters.
We know that for each character we have 62 different options.
And we have 10 characters.
Then the product between the numbers of options is:
C = 62^10
Then if the hacker does a random guess, the probability that the random guess is correct is one over the total number of possible combinations.
P = 1/C = 1/(62^10)
The probability that the hacker guesses the password on his first try is:
P = 1/(62^10) = 1.19*10^(-18)
If you want to read more about probability, you can read:
https://brainly.com/question/427252
Step 1: Choose the price of the house. Then calculate 20% (which will be your down payment). Write down the price and 20% of the price.
Step 2: You don't have 20% now, so you will use an annuity to save up until you have the 20%. Choose a time in the future (2 years, 3 years, 4 years, 5, 10?) that you will purchase this house. Choose an APR that the bank will give you. Calculate how much you need to deposit every month in order to have the 20% down payment down the road. Write down the numbers of years, the interest rate, the formula with all the numbers plugged in, and the monthly deposits you will need to make.
Step 3: Now you take out a mortgage on the remaining 80%. Choose an APR that the bank will charge you (to be realistic, more than the APR in step 2) and the time you will take to pay off the loan. Write down the formula with all the numbers plugged in, and write down the minimum monthly payments.
Please show me proper work and a step by step explanation on how you got your answers. Anyone who attempts to answer just to steal points will be reported. Btw this is due midnight tonight so I could really use some help with this
9514 1404 393
Answer:
$250,000 house price. $50,000 down payment2 years, 3% from the bank, monthly: $2024.065% APR, 30 years, monthly: 1073.64Step-by-step explanation:
1. House prices vary considerably. In January, 2021, the median US house price was about $269,000, growing at the rate of about 3.2% per year. For the purpose of this problem, we have chosen a slightly lower price of ...
$250,000 . . . selected house price
20% of this price is ...
0.20 × $250,000 = $50,000 . . . amount of down payment
__
2. House prices are growing faster than the interest rate we can get at the bank, so we want to minimize the amount of time we save for a down payment. At the same time, we recognize that saving this amount quickly will put a significant strain on the budget. We choose a period of 2 years, and assume a bank rate on savings of 3%. (US rates in mid-2021 average about 0.04%.) This annuity formula gives the future value of a series of payments:
A = P((1+r/12)^(12t)-1)(12/r) . . . . monthly payment P at annual rate r for t years
Solving for P, we have ...
P = A(r/12)/((1 +r/12)^(12t) -1)
Filling in the chosen numbers, we find we need to save ...
P = $50,000(0.03/12)/(1 +0.03/12)^(12·2) -1) = $50,000(0.0025)/0.06175704
P = $2024.06
$2024.06 needs to be deposited every month for 2 years at 3%.
__
3. The mortgage will be for ...
$250,000 -50,000 = $200,000
We assume we can get an APR of 5% on a 30-year loan. (US rates in mid-2021 are around 3.2%.) The formula for the payment amount is ...
A = P(r/12)/(1 -(1 +r/12)^(-12t)) . . . principal P at rate r for t years
Filling in the chosen numbers, we find the monthly payment to be ...
A = $200,000(0.05/12)/(1 -(1 +0.05/12)^(-12·30))
= $200,000(0.0041666667)/0.77617340 = $1073.64
The monthly mortgage payment will be $1073.64.
Finding Slope On a coordinate plane, a line goes through points (0, 1) and (4, 2). What is the slope of the line? m =
Answer:
slope = [tex]\frac{1}{4}[/tex]
Step-by-step explanation:
Calculate the slope m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (0, 1) and (x₂, y₂ ) = (4, 2)
m = [tex]\frac{2-1}{4-0}[/tex] = [tex]\frac{1}{4}[/tex]
Answer:
the answer would be 1/4
Step-by-step explanation:
please help brainliest to correct answer
Answer:
Question to number 6 is-3
Question to number 7 is 3
Question to number 8 is 2 to the second power
Step-by-step explanation:
please correct me if I’m wrong and for number 8 I am correct it’s just I didn’t know how to put the little 2 on top of the big one
Step-by-step explanation:
question 6 is - 3
question 7 is 3
question 8 is 4
Which of the following is true about congruent figures?
They're the same shape and the same size.
They're the same size, but not the same shape.
They're not the same shape or size.
They're the same shape, but not the same size.
Answer:
A
Step-by-step explanation:
congruent means they have the same shape and size. hope this helps :)
multiply 631.6 by 0.8
Answer: multiply 631.6 by 0.8 = 505.28
∫∫x²(y-x)dxdy ,d là miền giới hạn bởi các đường y=x² và x=y²
It looks like the integral is
[tex]\displaystyle \iint_D x^2 (y-x) \,\mathrm dx\,\mathrm dy[/tex]
where D is the set
D = {(x, y) : 0 ≤ x ≤ 1 and x ² ≤ y ≤ √x}
So we have
[tex]\displaystyle \iint_D x^2(y-x)\,\mathrm dx\,\mathrm dy = \int_0^1 \int_{x^2}^{\sqrt x} x^2(y-x)\,\mathrm dy\,\mathrm dx \\\\ = \int_0^1 \left(\frac{x^2y^2}2-x^3y\right)\bigg|_{y=x^2}^{y=\sqrt x} \\\\ = \int_0^1 \left(\frac{x^3}2-x^{7/2}+x^5-\frac{x^6}2\right)\,\mathrm dx \\\\ = \left(\frac{x^4}8 - \frac{2x^{9/2}}9 + \frac{x^6}6 - \frac{x^7}{14}\right)\bigg|_{x=0}^{x=1} = \frac18-\frac29+\frac16-\frac1{14} = \boxed{-\frac{1}{504}}[/tex]
Which of the following is the solution to the inequality below? -5x — 10 -6 B. x > -2 C. x <-6 D. x < -2
Answer:
x > -6
Step-by-step explanation:
-5x — 10 < 20
Add 10 to each side
-5x — 10+10 < 20+10
-5x < 30
Divide each side by -5, remembering to flip the inequality
-5x/-5 > 30/-5
x > -6
Answer:
x>-6Step-by-step explanation:
[tex]-5x - 10 < 20\\\\\mathrm{Add\:}10\mathrm{\:to\:both\:sides}\\\\-5x-10+10<20+10\\\\\mathrm{Multiply\:both\:sides\:by\:-1\:\left(reverse\:the\:inequality\right)}\\\\\left(-5x\right)\left(-1\right)>30\left(-1\right)\\\\\mathrm{Simplify}\\\\5x>-30\\\\\mathrm{Divide\:both\:sides\:by\:}5\\\\\frac{5x}{5}>\frac{-30}{5}\\\\x>-6[/tex]
If one card is randomly selected from a well-shuffled standard deck of 52 cards, what is the probability that the card selected is not a spade
Answer:
Step-by-step explanation:
Given
Total Number of Cards = 52
Required
Probability of not picking a spade
Let P(S) represents the probability of picking a spade;
[tex]P(S) = \frac{n(S)}{Total}[/tex]
Where n(S) is the number of spades
[tex]n(S) = 13[/tex]
Substitute [tex]n(S) = 13[/tex] and 52 for Total
[tex]P(S) = \frac{13}{52}[/tex]
[tex]P(S) = \frac{1}{4}[/tex]
Let P(S') represents the probability of not picking a spade
In probability;
[tex]P(S) + P(S') = 1[/tex]
Substitute [tex]P(S) = \frac{1}{4}[/tex]
[tex]\frac{1}{4} + P(S') = 1[/tex]
[tex]P(S') = 1 - \frac{1}{4}[/tex]
[tex]P(S') = \frac{4-1}{4}[/tex]
[tex]P(S') = \frac{3}{4}[/tex]
[tex]P(S') = 0.75[/tex]
Hence, the probability of not selecting a spade is 3/4 or 0.75
how many solutions does −6+2x=3x have?
Answer:
one solution
Step-by-step explanation:
−6+2x=3x
Subtract 2x from each side
−6+2x-2x=3x-2x
-6 = x
There is one solution
Answer:
it has 1 answer :)
Step-by-step explanation:
(a) A survey of the adults in a town shows that 8% have liver problems. Of these, it is also found that 25% are heavy drinkers, 35% are social drinkers and 40% are non-drinkers. Of those that did not suffer from liver problems, 5% are heavy drinkers, 65% are social drinkers and 30% do not drink at all. An adult is chosen at random, what is the probability that this person i. Has a liver problems? (3 Marks) ii. Is a heavy drinker (2 Marks) iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem? (2 Marks) iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker? (2 Marks) v. If a person is found to be a non –drinker, what is the probability that this person has liver problems. (2 Marks)
Answer:
i. Has a liver problems?
= 0.08
ii. Is a heavy drinker ?
= 0.066
iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem?
= 0.303
iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker?
= 0.25
v. If a person is found to be a non –drinker, what is the probability that this person has liver problems?
= 0.104
Step-by-step explanation:
We have 2 Events in this question
Event A: People with liver problems
Event B : People without liver problems
Event A: People with liver problems
Let us represent people with liver problems as = (L)
a)8% have liver problems. = P(L)
Under liver problems we have:
b) 25% are heavy drinkers = P( L & H)
c) 35% are social drinkers = P( L & S)
d) 40% are non-drinkers. = P( L & N)
Event B( no liver problem)
Let us represent no liver problem as NL
We are not given in the question but Probability of having no liver problem = 100 - Probability of having liver problem
= 100 - 8% = 92 %
P(NL ) = 92%
From the question, For people without liver problems, we have:
a) 5% are heavy drinkers = P(NL & H)
b) 65% are social drinkers = P( NL & S)
c) 30% do not drink at all = P( NL & N)
An adult is chosen at random, what is the probability that this person
i. Has a liver problems?
P(L) = 8% or 0.08
ii. Is a heavy drinker ?
From the question, we have:
Probability of people that have liver problems and are heavy drinkers P(L & H) = 25% = 0.25
Probability of people that have do not have liver problems and are heavy drinkers P(NL & H) = 5% = 0.05
Probability ( Heavy drinker) =
P(L) × P(L & H) + P(NL) × P(NL & H)
= 0.25 × 0.08 + 0.05 × 0.92
= 0.066
iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem?
Probability (Heavy drinker and has liver problem) = [P(L) × P(L & H)] ÷ [P(L) × P(L & H)] + [P(NL) × P(NL & H) ]
= [0.25 × 0.08] ÷ [0.25 × 0.08] + [0.05 × 0.92]
= 0.303030303
Approximately = 0.303
iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker?
P(L & H) = 25% = 0.25
v. If a person is found to be a non –drinker, what is the probability that this person has liver problems.?
People with liver problems are non-drinkers. = P( L & N) = 40% = 0.4
People without liver problems and do not drink at all = P( NL & N) = 30% = 0.3
Probability (non drinker and has liver problem) = [P( L & N) × P(L & H)] ÷ [P( L & N) × P(L & H)] + [ P( NL & N) × P(NL & H) ]
= [0.4× 0.08] ÷ [0.4 × 0.08] + [0.3 × 0.92]
= 0.1038961039
Approximately ≈ 0.104
Solve the polynomial x² - 7x + 12 = 0 Show each step used to find the solutions.
Answer:
x=4 and x=3
Step-by-step explanation:
The first step to find all factors of 12
1,2,3,4,6,12
and their negative form
-1,-2,-3,-4,-6,-12
we must add two of these numbers to get -7
and the two numbers that add up to -7 are -3 and -4
we can simply plot them into the polynomial (x-3)(x-4)
since x-3=0
we add three to both sides to get x=3
and since x-4=0
add four to both sides
we get x=4
and now check out work which
we can use First out in last (foil) method
(x-3)(x-4)
first
x^2
out
-4x
in
-3x
last
12
now we simplify to get x^2-7x+12
so it x=4 x=3 works
Answer:
x² - 7x + 12 = 0
doing middle term factorization
x²-4x-3x+12=0
taking common from each two term
x(x-4)-3(x-4)=0
taking common
(x-4)(x-3)=0
either
x-4=0
:. x=4
or
x-3=0
x=3
:.x=4,3
A ball is thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s(t)=224t−16t. After how many seconds will the ball be 720 feet from the ground?
Answer:
s= 16t^2+128t, answer.......
Gerald graphs the function f(x) = (x – 3)2 – 1. Which statements are true about the graph? Select three options.
Answer:
The answer is "Choice B, C, and F is correct".
Step-by-step explanation:
The following are choices, which is missing in the question, that can be defined as follows:
A) {x| x ≥ 3} is the domain.
B) The set shall be {y| y ≥ –1}.
C) over the interval (–∞, 3), is the function, that decreases.
D) it's over the duration the function increases its value, that is (–1, ∞).
E) The symmetry axis will be x = – 1.
F) vertex is (3, – 1).
In choice A, It is incorrect even though f is the domain, which is all true numbers because it has a quadrant function. In choice B, it is correct. In choice C, It is valid because it was a parable open with vertex so if we exploded view f (3, -1). Because as value opens up, its value with x from-∞ to 3 drops while it goes up from increasing from 3 to ∞. In choice D, It is wrong since we have just said f decreases from-∞ to 3. Therefore, f decreases from -1 to 3, too. Therefore, f doesn't grow from -1 to ∞. In choice E, It is incorrect because the symmetry axis is x = 3. In choice F, it is true.Answer:
the answers are b, c, e
Step-by-step explanation:
i just took the test
we make a sequence of figures with tiles. The first four figures have 1,4,7 and 10 tiles, respectively. How many tiles will the 15th figure have?
Answer:
43
Step-by-step explanation:
1 , 4 , 7 , 10
→ Find the difference between each term
4 - 1 = 3, 7 - 4 = 3 and 10 - 7 = 3
→ Put this into the nth term format
3n + x
→ Write the 3 times tables above the sequence and find what you need to take away from the times tables to get to the sequence
3 , 6 , 9 , 12
1 , 4 , 7 , 10
→ Minus 2
3n - 2
→ Substitute 15 as n
3 × 15 - 2 = 43
I dont understand this please help Which expression represents the area of the shaded region
Answer:
I'm gonna say C
The equation below is written in words. x plus ten equals two. What's the value of x?
Answer:
x+10 =2
x = -8
Step-by-step explanation:
plus means add
x+10 =2
Subtract 10 from each side
x+10-10 =2-10
x = -8
A study was conducted to assess the effects that occur when children are exposed to cocaine before birth. Children were tested at age 4 for object assembly skill, which was described as a task requiring visual spatial skills related to mathematical competence. The 190 children born to cocaine users had a mean of 7.3 and a standard deviation of 3.0 The 186 children not exposed to cocaine had a mean score of 8.2 with a standard deviation of 3.0 Use a 0.05 significance level to test the claim that prenatal cocaine exposure is associated with lower scores of four year old children on the test of object assembly.
What are null and alternative hypothesis? What is test statistics?
Answer:
We conclude that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly.
Step-by-step explanation:
We are given that the 190 children born to cocaine users had a mean of 7.3 and a standard deviation of 3.0 The 186 children not exposed to cocaine had a mean score of 8.2 with a standard deviation of 3.0.
Let [tex]\mu_1[/tex] = population mean score for children born to cocaine users.
[tex]\mu_2[/tex] = population mean score for children not exposed to cocaine.
So, Null Hypothesis, : = 490 {means that the prenatal cocaine exposure is not associated with lower scores of four-year-old children on the test of object assembly}
Alternate Hypothesis, : 490 {means that the prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly}
The test statistics that will be used here is Two-sample t-test statistics because we don't know about population standard deviations;
T.S. = [tex]\frac{(\bar X_1-\bar X_2)-(\mu_1-\mu_2)}{s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }[/tex] ~ [tex]t__n_1_+_n_2_-_2[/tex]
where, [tex]\bar X_1[/tex] = sample mean score of children born to cocaine users = 7.3
[tex]\bar X_2[/tex] = sample mean score of children not exposed to cocaine = 8.2
[tex]s_1[/tex] = sample standard deviation for children born to cocaine users = 3
[tex]s_2[/tex] = sample standard deviation for children not exposed to cocaine = 3
[tex]n_1[/tex] = sample of children born to cocaine users = 190
[tex]n_2[/tex] = sample of children not exposed to cocaine = 186
Also, [tex]s_p=\sqrt{\frac{(n_1-1)\times s_1^{2}+(n_2-1)\times s_2^{2} }{n_1+n_2-2} }[/tex] = [tex]\sqrt{\frac{(190-1)\times 3^{2}+(186-1)\times 3^{2} }{190+186-2} }[/tex] = 3
So, the test statistics = ~
= -2.908
The value of t-test statistics is -2.908.
Now, at a 0.05 level of significance, the t table gives a critical value of -1.645 at 374 degrees of freedom for the left-tailed test.
Since the value of our test statistics is less than the critical value of t as -2.908 < -1.645, so we have sufficient evidence to reject our null hypothesis as the test statistics will fall in the rejection region.
Therefore, we conclude that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly.
In the null hypothesis, a test always forecasts no effect, while the alternate theory states the research expectation impact, and calculation as follows:
Null and alternative hypothesis:Calculating the pooled estimator of [tex]\sigma^2[/tex], denoted by [tex]S^2_p[/tex], is defined by
[tex]\to \bold{S^2_p= \frac{(n_1 - 1) S^2_1+ (n_2 - 1)S^2_2}{n_1 + n_2 - 2}}[/tex]
Null hypothesis:
[tex]\to H_0 : \mu_1 - \mu_2 = \Delta_0\\[/tex]
Test statistic:
[tex]\to T_0=\frac{\bar{X_1}- \bar{X_2} -\Delta_0}{S_p \sqrt{\frac{1}{n_1}+\frac{1}{n_2}}} \\\\[/tex]
Alternative Hypothesis:
[tex]H_1 : \mu_1 -\mu_2 \neq \Delta_0\\\\ H_1 : \mu_1 -\mu_2 > \Delta_0\\\\H_1 : \mu_1 -\mu_2 < \Delta_0\\\\[/tex]
Rejection Criterion
[tex]t_0 > t_{\frac{\alpha}{2} , n_1+n_2 -2}\ \ \ or\ \ \ t_0 < - t_{\frac{\alpha}{2} , n_1+n_2 -2} \\\\t_o > t_{\alpha , n_1+n_2 -2} \\\\t_o > -t_{\alpha , n_1+n_2 -2}[/tex]
Given value:
[tex]\to S_p=9\\\\\to \Delta_0=0\\\\\to t_0=-\frac{0.9}{3(\sqrt{(\frac{1}{190}+\frac{1}{186})})}=-2.9\\\\\to t_{0.05,374}=1.645\\\\[/tex]
here
[tex]\to t_0 < -t_{0.05,374}[/tex]
hence rejecting the [tex]H_0[/tex]
Since there should be enough evidence that prenatal cocaine exposure is linked to inferior item assembly scores in 4-year-olds.
Find out more about the alternative hypothesis here:
brainly.com/question/18831983