I don’t understand this

Answer: The population was 2,300,000.

Step-by-step explanation:

Let the population in 1950 be x

11,200,000 = 2,000,000+4x

11,200,000-2,000,000 = 4x

0r, 9,200,000=4x

0r, x = 9,200,000/4

so, x = 2,300,000

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]

Answer:

A

Step-by-step explanation:

congruent means they have the same shape and size. hope this helps :)

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

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:

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

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

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]

Step-by-step explanation:

Putting values

A = - 7(15 + 9)

A = - 7(24)

A = - 168

Answer:

the size of the square to be cut out for maximum volume is 1.5695 inches

Step-by-step explanation:

cardboard that measures 8 by 12 inches.

We need to determine What size square should be cut from each corner

We were given given the size of the cardboard.

let us denote the length of the square as 'x'.

Then our length, width and height will be:

Length = 8 − 2x

Width = 12− 2x

Then our Height = x

So now, the volume= length×width ×height

Volume = (8 − 2x) x (12− 2x) x (x)

After calculating volume comes out to be:

V = (96 − 40x + 4x²) (x)

V = 4x³ − 40x² + 96x

Now, we can use differentiation to equate it to zero.

So differentiate it with respect to x, we get

dV/dx = 12x² − 80x + 96

12x² − 80x + 96 = 0

So, after solving this, x comes out to be:

x = 5.097 and x = 1.5695

Looking at it the size of the square cut out cannot be 5.097 because we cannot cut out of both sides of the width, since the width is 5 inches.

Therefore, the size of the square to be cut out for maximum volume is 1.5695 inches.

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

Monster Truck show. Before the show, Troy got to see

the trucks close up. He noticed that each monster truck tire had a radius of

about 3 feet.

9514 1404 393

Answer:

Step-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.

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

Answer:

PLATO ANSWER

Step-by-step explanation:

x2 − x − 72

-8x + 56

5

those are the correct answers

Answer:

j7kd4uzvinxru,en gg4ukfiebcjeictijxc7t

Step-by-step explanation:

mxrICE vxxn6rj CVT ryrf NYC cfkxkeuixx BBC xu BBC yfh

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]

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

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

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:

[tex]\\ \sf\longmapsto 112^2[/tex]

[tex]\\ \sf\longmapsto (100+12)^2[/tex]

[tex]\\ \sf\longmapsto 100^2+2(100)(12)+12^2[/tex]

[tex]\\ \sf\longmapsto 10000+2400+144[/tex]

[tex]\\ \sf\longmapsto 12400+144[/tex]

[tex]\\ \sf\longmapsto 12544[/tex]

112²

(a + b)² = (a² + 2ab + b²)

⇛112²

⇛(100 + 12)²

⇛(100)² + 2 × 100 × 12 + (12)²

⇛10000 + 2400 + 144

⇛12400 + 144

⇛12544

Answer:

x = 17/5

y = -2/5

Step-by-step explanation:

2x + 2y = 6

3x - 2y = 11

sum both equations results

5x + 0 = 17

x = 17/5

2x + 2y = 6

2*17/5 + 2y = 6

34/5 + 2y = 6

2y = 6 - 34/5

2y = 30/5 - 34/5

2y = -4/5

y = (-4/5)/2

y = -2/5

verify:

3x - 2y = 11

3*17/5 - 2*-2/5 = 11

51/5 + 4/5 = 55/5

51 + 4 = 55

Answer:

Step-by-step explanation:

The first thing you want to do is to factor in any quadratic equation.

So, -10(x^2-25)

Now, we see this is a special case, whenever we see a equation in this case, x^2 - b^2, we factor it to this (x+b)(x-b)

So, -10(x+5)(x-5)

x = -5 and x = 5

Answer:

1200 ×90÷8 is not correct ans

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:

Answer: multiply 631.6 by 0.8​ = 505.28

Answer:

z(s) is in the acceptance region. We accept H₀  we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine

Step-by-step explanation:

We must evaluate the differences of the means of the two machines, to do so, we will assume a CI  of 95%, and as the interest is to find out if the new machine has better performance ( machine has a bigger efficiency or the new machine produces more units per unit of time than the old one) the test will be a one tail-test (to the left).

New machine

Sample mean                  x₁ =    25

Sample variance               s₁  = 27

Sample size                       n₁  = 45

Old machine

Sample mean                    x₂ =  23  

Sample variance               s₂  = 7,56

Sample size                       n₂  = 36

Test Hypothesis:

Null hypothesis                         H₀             x₂  -  x₁  = d = 0

Alternative hypothesis             Hₐ            x₂  -  x₁  <  0

CI = 90 %  ⇒  α =  10 %     α = 0,1      z(c) = - 1,28

To calculate z(s)

z(s)  =  ( x₂  -  x₁ ) / √s₁² / n₁  +  s₂² / n₂

s₁  = 27     ⇒    s₁²  =  729

n₁  = 45    ⇒   s₁² / n₁    = 16,2

s₂  = 7,56   ⇒    s₂²  = 57,15

n₂  = 36     ⇒    s₂² / n₂  =  1,5876

√s₁² / n₁  +  s₂² / n₂  =  √ 16,2  + 1.5876    = 4,2175

z(s) = (23 - 25 )/4,2175

z(s)  =  - 0,4742

Comparing z(s) and  z(c)

|z(s)| < | z(c)|  

z(s) is in the acceptance region. We accept H₀  we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine

The very hight dispersion of values s₁ = 27 is evidence of frecuent values quite far from the mean

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

Answer:

s= 16t^2+128t, answer.......

Explanation:

I used GeoGebra to determine that the approximate solutions in (x,y) form are

(0.00333, 0)

(9.59682, 3.45925)

These are the locations where the two graphs cross or intersect.

When rounding to the nearest tenth, we end up with (0, 0) and (9.6, 3.5) which is why the answers are D and E.

Be careful to keep in mind that x = 0 is not in the domain of g(x) since log(0) is undefined. So it's fairly misleading to say that (0,0) is an intersection point when it's not even on the graph of g(x). This is one big issue with rounding numbers that we lose crucial information like this.

Answer:

Hello,

x=9.59682

Step-by-step explanation:

Using Excel with the methode of "dichotomie" (divide by 2)

Just modifiy value in A2(start value)  and E1 (precision)

Answer:

B

Step-by-step explanation:

16,x+4

by completing square formula