Complete Question
Statistics professors believe the average number of headaches per semester for all students is more than 18. From a random sample of 15 students, the professors find the mean number of headaches is 19 and the standard deviation is 1.7. Assume the population distribution of number of headaches is normal.the correct conclusion at [tex]\alpha =0.001[/tex] is?
Answer:
There is no sufficient evidence to support the professor believe
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 18[/tex]
The sample size is [tex]n = 15[/tex]
The sample mean is [tex]\= x = 19[/tex]
The standard deviation is [tex]\sigma = 1.7[/tex]
The level of significance is [tex]\alpha = 0.001[/tex]
The null hypothesis is [tex]H_o: \mu = 18[/tex]
The alternative hypothesis is [tex]H_a : \mu > 18[/tex]
The critical value of the level of significance from the normal distribution table is
[tex]Z_{\alpha } = 3.290527[/tex]
The test hypothesis is mathematically represented as
[tex]t = \frac{\= x - \mu }{ \frac{\sigma}{ \sqrt{n} } }[/tex]
substituting values
[tex]t = \frac{ 19 - 18}{ \frac{1.7}{ \sqrt{15} } }[/tex]
[tex]t = 2.28[/tex]
Looking at the value of t and [tex]Z_{\alpha }[/tex] we can see that [tex]t < Z_{\alpha }[/tex] so we fail to reject the null hypothesis.
This mean that there is no sufficient evidence to support the professor believe
The recipe for gelatin uses 2 cups of water with 4 packages of the gelatin mix. ? How many cups of water will be used with 12 packages of gelatin mix?
Step-by-step explanation:
2 cups of water used with 4 packs
therefore for 12 we use x cups of water
2:4
X :12
therefore 6'cups of water?
How do you solve an expansion?
[tex]\displaystyle\\(a+b)^n\\T_{r+1}=\binom{n}{r}a^{n-r}b^r\\\\\\(x+2)^7\\a=x\\b=2\\r+1=5\Rightarrow r=4\\n=7\\T_5=\binom{7}{4}x^{7-4}2^4\\T_5=\dfrac{7!}{4!3!}\cdot x^3\cdot16\\T_5=16\cdot \dfrac{5\cdot6\cdot7}{2\cdot3}\cdot x^3\\\\T_5=560x^3[/tex]
Answer:
[tex]\large \boxed{560x^3}[/tex]
Step-by-step explanation:
[tex](x+2)^7[/tex]
Expand brackets.
[tex](x+2) (x+2) (x+2) (x+2) (x+2) (x+2) (x+2)[/tex]
[tex](x^2 +4x+4) (x^2 +4x+4) (x^2 +4x+4)(x+2)[/tex]
[tex](x^4 +8x^3 +24x^2 +32x+16)(x^3 +6x^2 +12x+8)[/tex]
[tex]x^7 +14x^6 +84x^5 +280x^4 +560x^3 +672x^2 +448x+128[/tex]
The fifth term is 560x³.
where p is the price (in dollars) and x is the number of units (in thousands). Find the average price p on the interval 40 ≤ x ≤ 50. (Round your answer to two decimal places.)
THIS IS THE COMPLETE QUESTION BELOW
The demand equation for a product is p=90000/400+3x where p is the price (in dollars) and x is the number of units (in thousands). Find the average price p on the interval 40 ≤ x ≤ 50.
Answer
$168.27
Step by step Explanation
Given p=90000/400+3x
With the limits of 40 to 50
Then we need the integral in the form below to find the average price
1/(g-d)∫ⁿₐf(x)dx
Where n= 40 and a= 50, then if we substitute p and the limits then we integrate
1/(50-40)∫⁵⁰₄₀(90000/400+3x)
1/10∫⁵⁰₄₀(90000/400+3x)
If we perform some factorization we have
90000/(10)(3)∫3dx/(400+3x)
3000[ln400+3x]₄₀⁵⁰
Then let substitute the upper and lower limits we have
3000[ln400+3(50)]-ln[400+3(40]
30000[ln550-ln520]
3000[6.3099×6.254]
3000[0.056]
=168.27
the average price p on the interval 40 ≤ x ≤ 50 is
=$168.27
Find the value of a and YZ if Y is between X and Z. XY = 7a, YZ = 5a, XZ = 6a + 24 = YZ =
[tex]\\ \sf\longmapsto XY+YZ=XZ[/tex]
[tex]\\ \sf\longmapsto 7a+5a=6a+24[/tex]
[tex]\\ \sf\longmapsto 12a=6a+24[/tex]
[tex]\\ \sf\longmapsto 12a-6a=24[/tex]
[tex]\\ \sf\longmapsto 6a=24[/tex]
[tex]\\ \sf\longmapsto a=\dfrac{24}{6}[/tex]
[tex]\\ \sf\longmapsto a=5[/tex]
YZ=5a=5(5)=25Value of a is 4 and value of YZ is 20 units
Step-by-step explanation:
Given:
Y is between point X and Z
Value of line XY = 7a
Value of line YZ = 5a
Value of line XZ = 6a + 24
Find:
Value of "a" and line YZ
Computation:
We know that
XY + YZ = XZ
So,
7a + 5a = 6a + 24
12a = 6a + 24
6a = 24
a = 4
Value of a = 4
So,
Value of line YZ = 5a
By putting value of a
Value of line YZ = 5(4)
Value of line YZ = 20 units
Learn more;
https://brainly.com/question/18983323?referrer=searchResults
What does the tape measure say Measurement # 4 is?
Answer:
It looks like 6 and one eighth of an inch.
Determine what type of model best fits the given situation:
The temperature of a cup of coffee decreases by 5 F every 20 minutes.
Solve for x step by step:
2(4x-3)-8=4+2x
Answer:
3
Step-by-step explanation:
2(4x-3)-8=4+2x
8x - 6 - 8 = 4 + 2x
8x - 2x = 4 + 6 + 8
6x = 18
x = 18/6
x = 3
Answer:
[tex]2(4x - 3) - 8 = 4 + 2x \\ 2 \times 4x + 2 \times - 3 - 8 = 4 + 2x \\ according \: to \: bodmas \: first \: \times then + or - \\ so \\ 8x - 6 - 8 = 4 + 2x \\ 8x - 14 = 4 + 2x \\ 8x - 2x = 4 + 14 \\ 6x = 18 \\ x = \frac{18}{6} \\ x = 3 \\ thank \: you[/tex]
Which of these functions could have been the graph shown below?
Answer:
B
Step-by-step explanation:
we take the only point we know
(0,20)
in A when x =0
[tex]f(x)=e^{20x} =e^{20*0}=1[/tex]
in B when x=0
[tex]f(x)=20e^x=20e^0=20*1=20[/tex]
fits
in C
[tex]f(x)=20^x=20^0=1[/tex]
in D
[tex]f(x)=20^{20x}=20^{20*0}=20^0=1[/tex]
so the only choice is B
Lorene plans to make several open-topped boxes in which to carry plants. She makes the boxes from rectangular sheets of cardboard from which she cuts out - squares from each corner. The length of the original piece of cardboard is more than the width. If the volume of the box is , determine the dimensions of the original piece of cardboard.
Question is not complete, so i have attached it.
Answer:
Length = 30 inches
Width = 22 inches
Step-by-step explanation:
Let the width of rectangular sheet be x inches.
Let the length of the sheet be (x + 8) inches.
Now, after she cuts 4 inches squares from each corner, she will get a box of length: x + 8 - 4 - 4 = x inches , width: (x - 8) inches and height 4 inches.
Now, volume of a cube is;
V = lwh
Thus;
V = x(x - 8)(4)
We are told that the volume of the box is 2640 in³
Thus;
x(x - 8)(4) = 2640
Divide both sides by 4 to get;
x(x - 8) = 660
x² - 8x - 660 = 0
Using quadratic formula, we have;
x = 30 or - 22.
We will use x = 30 as the other one is negative.
Since we earlier deduced that she will get a box of will get a box of length: x inches , width: (x - 8) inches
Thus,
Length = 30 inches
Width = 30 - 8 = 22 inches
there are 40 marbles in an urn: 14 are green and 26 are yellow. you reach into the urn and randomly select 4 marbles without replacement. what is the probability that at least one of the marbles is green
Answer:
p=0,83641536
Step-by-step explanation:
Let's calculate the probability that all 4 marbles are yellow:
p=26/40*25/39*24/38*23/37 ( no replacement)
=0,1635846372688....
probability that at least one of the marbles is green= 1-p
=0,83641536...
There are 2229 students in a school district. Among a sample of 452 students from this school district, 163 have mathematics scores below grade level. Based on this sample, estimate the number of students in this school district with mathematics scores below grade level.
a. 804
b. 844
c. 884
d. 0.36
Answer:
A. 804Step-by-step explanation:
Given the total number of students in the school to be 2229 students. If among a sample of 452 students from this school district, 163 have mathematics scores below grade level, then we can determine the number of students in this school district with mathematics scores below grade level based on the sample scores using ratio.
Let the number of students in this school district with mathematics scores below grade level be x. The ratio of the students with math score below grade level to total population will be x:2229
Also, the ratio of the sample students with math score below grade level to sample population will be 163:452
On equating both ratios, we will have;
x:2229 = 163:452
[tex]\dfrac{x}{2229} = \dfrac{163}{452}\\ \\cross\ multiplying;\\\\\\452*x = 2229*163\\\\x = \dfrac{2229*163}{452}\\ \\x = \frac{363,327}{452}\\ \\x = 803.8\\\\x \approx 804[/tex]
Hence the estimate of the number of students in this school district with mathematics scores below grade level based on the sample is 804
I need help ASAP please please please
Answer:
n=39/5
Step-by-step explanation:
24=5(n-3)
24=5n-15
-5n= -15-24
-5n=39
n= 39/5
Assuming that the loss of ability to recall learned material is a first-order process with a halflife of 35 days. Compute the number of days required to forget 90% of the material that you have learned today. Report to 1 decimal place.
Answer:
5.3 days
Step-by-step explanation:
Let us assume the loss of ability to recall a learned material = 100%
Formula to calculate number of days = time(t) =
t = t½ × Log½(Nt/No)
Nt = Ending Amount
No = Beginning Amount
t½ = Half life
t = Time elapsed
Therefore, we have the following values from the questions:
Half life (t½)= 35 days
Initial or beginning amount = 100%
Ending amount = 90%
t = t½ × Log½ (Nt/No)
t = 35 × Log ½(90/100)
t = 5.3201082705768 days
Approximately = 5.3 days
[tex]4 + \frac{4}{4 } \: = [/tex]
what is answer
Answer:
5Step-by-step explanation:
[tex]4 + \frac{4}{4} [/tex]
= 4 + 1
= 5 (Ans)
The PTA sells 100 tickets for a raffle and puts them in a bowl. They will randomly pull out a ticket for the first prize and then another ticket for the second prize. You have 10 tickets and your friend has 10 tickets. What is the probability that your friend wins the first prize and you win the second prize?
5 A machine puts tar on a road at the rate of 4 metres in 5 minutes.
a) How long does it take to cover 1 km of road
b) How many metres of road does it cover in 8 hours?
Answer:
5 a) Total = 20.83 hrs = 20 hrs and 50 mins (1250mins total)
5 b) Total = 96 meters. = 0.096km in 8 hrs.
Step-by-step explanation:
1km = 1000 meters
5 mins = 4 meters
1000/4 = 250 multiplier
250 x 5mins = 1250 minutes
1250/60 = 20hrs + 50 minutes
50 / 60 = 0.83 = 20.83hrs
b) 8 hrs = 8 x 60 = 480 minutes
480/5 = 24 multiplier of 4 meters
24 x 4 = 96 meters
Complete the pattern ___ 8,579 ____85.7 8.57____
Answer:
the next one is .857 I hope this helps you :)
One model of the length LACL of a person's anterior cruciate ligament, or ACL, relates it to the person's height h with the linear function LACL=0.04606h−(41.29 mm) This relationship does not change significantly with age, gender, or weight. If a basketball player has a height of 2.13 m, approximately how long is his ACL?
Answer:
The [tex]L_{ACL}[/tex] of the player is [tex]L_{ACL} = 56.82 \ mm[/tex]
Step-by-step explanation:
From the question we are told that
The relationship between the length [tex]L_{ACL}[/tex] to the height is
[tex]L_{ACL} = 0.04606h - (41.29 \ mm)[/tex]
The height of the basketball player is [tex]h = 2.13 \ m = 2130 \ mm[/tex]
Substituting the value of height of the basket ball player in to the model we have the [tex]L_{ACL}[/tex] of the player is
[tex]L_{ACL} = 0.04606 (2130) - (41.29 ) \ mm[/tex]
[tex]L_{ACL} = 56.82 \ mm[/tex]
The graph below represents the function f.
f(x)
if g is a quadratic function with a positive leading coefficient and a vertex at (0,3), which statement is true?
А.
The function fintersects the x-axis at two points, and the function g never intersects the x-axis.
B
The function fintersects the x-axis at two points, and the function g intersects the x-axis at only one point.
c.
Both of the functions fand g intersect the x-axis at only one point.
D
Both of the functions fand g intersect the x-axis at exactly two points.
Answer: А.
The function f intersects the x-axis at two points, and the function g never intersects the x-axis.
Step-by-step explanation:
In the graph we can see f(x), first let's do some analysis of the graph.
First, f(x) is a quadratic equation: f(x) = a*x^2 + b*x + c.
The arms of the graph go up, so the leading coefficient of f(x) is positive.
The vertex of f(x) is near (-0.5, -2)
The roots are at x = -2 and x = 1. (intersects the x-axis at two points)
Now, we know that:
g(x) has a positive leading coefficient, and a vertex at (0, 3)
As the leading coefficient is positive, the arms go up, and the minimum value will be the value at the vertex, so the minimum value of g(x) is 3, when x = 0.
As the minimum value of y is 3, we can see that the graph never goes to the negative y-axis, so it never intersects the x-axis.
so:
f(x) intersects the x-axis at two points
g(x) does not intersect the x-axis.
The correct option is A.
Answer:
The answer is A.) The function f intersects the x-axis at two points, and the function g never intersects the x-axis.
Step-by-step explanation:
I took the test and got it right.
An online polling site posed this question: "How much stock do you put in long-range weather forecasts?" Among its Web site users, 38, 528 chose to respond Complete parts (a) through (c) below.
a. Among the responses received, 3% answered with "a lot". What is the actual number of responses consisting of "a lot"?
b. Among the responses received, 18, 566 consisted of "very little or none". What percentage of responses consisted of "very little or none"?
c. Because the sample size of 38, 528 is so large, can we conclude that about 3% of the general population puts "a lot" of stock in long-range weather forecasts? Why or why not?
A. No, because the sample is a voluntary response sample, so the sample is not likely to be representative of the population.
B. Yes, because the sample is so large, the margin of error is negligible.
C. No, because even though the sample size is so large, there is still a margin of error.
D. Yes, because the sample size is large enough so that the sample is representative of the population.
Answer:
(a) 1155.84
(b) 48.2%
(c) D
Step-by-step explanation:
The number of total responses is, N = 38,528.
(a)
It is provided that 3% answered with "a lot".
Compute the actual number of responses consisting of "a lot" as follows:
n (a lot) = N × P (a lot)
= 38528 × 0.03
= 1155.84
Thus, the actual number of responses consisting of "a lot" is 1155.84.
(b)
The number of responses consisting of "very little or none" is,
n (very little or none) = 18,566
Compute the percentage of responses consisted of "very little or none" as follows:
[tex]P(\text{very little or none})=\frac{n(\text{very little or none})}{N}[/tex]
[tex]=\frac{18566}{38528}\\\\=0.481883\\\\\approx 0.482[/tex]
The percentage is: 0.482 × 100% = 48.2%.
Thus, the percentage of responses consisted of "very little or none" is 48.2%.
(c)
As the sample size increases the sample statistic value gets closer and closer to the actual population parameter value.
Thus, making the sample statistic an unbiased estimator of the population parameter.
And proving that the sample is a true representative of the population.
Thus, the correct option is (D).
What are the coordinates of the point (2,-4) under the dilation D-2?
A) (8,-4)
B) (4,-8)
C) (-8,4)
D) (-4,8)
Answer:
D) (-4,8)
Step-by-step explanation:
Multiply both coordinates by -2
Answer:
(-4,8)
Step-by-step explanation:
I found a school pdf with the answer key to this exact equation and thats the answer
Picking a card and spinning a spinner are independent events.
True
False
Answer:
True
Step-by-step explanation:
Both happened in different times and are seprate events
Alice, Bob, and Carol play a chess tournament. The first game is played between Alice and Bob. The player who sits out a given game plays next the winner of that game. The tournament ends when some player wins two successive games. Let a tournament history be the list of game winners, so for example ACBAA corresponds to the tournament where Alice won games 1, 4, and 5, Caroll won game 2, and Bob won game 3.
Required:
a. Provide a tree-based sequential description of a sample space where the outcomes are the possible tournament histories.
b. We are told that every possible tournament history that consists of k games has probability 1/2k, and that a tournament history consisting of an infinite number of games has zero prob- ability. Demonstrate that this assignment of probabilities defines a legitimate probability law.
c. Assuming the probability law from part (b) to be correct, find the probability that the tournament lasts no more than 5 games, and the probability for each of Alice, Bob, and Caroll winning the tournament.
Answer:
I don't know what you think about it is not going to be a great day of school and I don't know what you think about it is not going to be a great day of school
Find the missing side or angle.
Round to the nearest tenth.
Answer:
[tex] b = 2.7 [/tex]
Step-by-step explanation:
Given:
< C = 53°
< B = 80°
a = 2
Required:
Find b
Solution:
The question given suggests we are given measures for a ∆.
To find side b, which corresponds to angle B, first, we'd find angle A, which corresponds to side a, then apply the Law of sines to find side b.
=> A = 180 - (53 + 80) = 47°
Law of Sines: [tex] \frac{a}{sin(A} = \frac{b}{sin(B} [/tex]
Plug in the values into the formula
[tex] \frac{2}{sin(47} = \frac{b}{sin(80} [/tex]
Cross multiply
[tex] 2*sin(80) = b*sin(47) [/tex]
Divide both sides by sin(47) to make b the subject of formula
[tex] \frac{2*sin(80)}{sin(47} = b [/tex]
[tex] 2.69 = b [/tex]
[tex] b = 2.7 [/tex] (nearest tenth)
Please help me I will mark brainliest! The ratio of the number of boys to the number of girls in a school is 3:4. One-third of the boys and three-eighths of the girls wear spectacles, If there are 612 pupils who do not wear spectacles, a)find the total number of the pupils in the school, and b) how many more girls than boys are there in the school
Answer:
a) 952
b) 136
Step-by-step explanation:
Ratio of b:g = 3:4, based on this we have:
Number of boys = 3xNumber of girls = 4xTotal number of pupils = 3x+4x = 7xNumber of spectacle wearers:
1/3*3x + 3/8*4x = x + 3/2x = 2.5xNumber of those not wearing spectacles:
7x - 2.5x= 4.5xAnd this number equals to 612, then we can find the value of x:
4.5 x = 612x= 612/4.5x= 136a) Total number of pupils:
7x = 7*136 = 952b) The difference in the number of boys and girls:
4x-3x= x = 136Answer:
total number of students: 952
number of girls more than boys :136 more girls
Step-by-step explanation:
1/3 of boys +3/8 girls= spectacles
612 people do not wear spectacles
3:4= boys: girls
total number of students
3+4=7
boys + girls = total ratio
7= total ratio
1/3×3=1 3/8×4=3/2
1+3/2=5/2
7-5/2=9/2 9/2=612 students
If 9/2=612 Then 7=?
7= 7÷ 9/2×612
=952 people
Girls more than boys
if 7= 952
3= 3/7 × 952=408 boys
if 7 = 952
4= 4/7 ×952=544girls
Girls - boys
544- 408 = 136 girls
3) Write the operation used to obtain the types of solutions.
Sum:
Difference:
Product:
Quotient:
Answer:
the Sum
hope this helps
find x on the lines plz and thanks
Answer:
x = 9
this is a ratio problem. You can see that 12/6 = 2, so you can also take 18/2 to get 9.
Answer:
the answer is 6
Step-by-step explanation:
Because 6 and x are corresponding angle so that means no matter what ( if u want the answer to how long the line is or what degree the angle is ) the answer is always going to be the same as the one above ( which is 6 )
Hop this helpssss
Can someone please help me with this math problem
We have [tex]f\left(f^{-1}(x)\right) = x[/tex] for inverse functions [tex]f(x)[/tex] and [tex]f^{-1}(x)[/tex]. Then if [tex]f(x) = 2x+5[/tex], we have
[tex]f\left(f^{-1}(x)\right) = 2f^{-1}(x) + 5 = x \implies f^{-1}(x) = \dfrac{x-5}2[/tex]
Then
[tex]f^{-1}(8) = \dfrac{8-5}2 = \boxed{\dfrac32}[/tex]
Keith tabulated the following values for time spent napping in minutes of six of his friends: 23, 35, 17, 30, 20, and 19. The standard deviation is 7.043 Keith reads that the mean nap is 22 minutes. The t-statistic for a two-sided test would be __________. Answer choices are rounded to the hundredths place. 1.39 or 1.43 or 2.88 or 0.70
Answer:
The t-statistic is [tex]t = 0.6956[/tex]
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 22 \ minutes[/tex]
The standard deviation is [tex]s = 7.043[/tex]
The given data is 23, 35, 17, 30, 20, and 19.
Generally the sample mean is mathematically evaluated as
[tex]\= x = \frac{23+ 35+17+ 30+ 20+ 19 }{6}[/tex]
[tex]\= x =24[/tex]
The t-statistic is mathematically evaluated as
[tex]t = \frac{ \= x - \mu }{\frac{s}{ \sqrt{n} } }[/tex]
=> [tex]t = \frac{ 24 - 22 }{\frac{ 7.043}{ \sqrt{6} } }[/tex]
=> [tex]t = 0.6956[/tex]
Answer: 0.70
Step-by-step explanation:
given the vector with a manitude of 9m at an angle a of -80 degrees, decompose this vector into two vector components oarallel to the x axis with a slope of
Answer:
We have the magnitude, M, and the angle A.
(The angle is always measured from the +x-axis)
Then we have that:
x = M*cos(A)
y = M*sin(A)
in this case:
M = 9m
A = -80°
x = 9m*cos(-80°) = 1.562
y = 9m*sin(-80) = -8.86m
Now, the component parallel to the x axis is:
x = 9m*cos(-80°) = 1.562 m
And the slope of something parallel to the x-axis is always zero, as this is a constant line.