The president of a university claimed that the entering class this year appeared to be larger than the entering class from previous years but their mean SAT score is lower than previous years. He took a sample of 20 of this year's entering students and found that their mean SAT score is 1,501 with a standard deviation of 53. The university's record indicates that the mean SAT score for entering students from previous years is 1,520. He wants to find out if his claim is supported by the evidence at a 5% level of significance. Referring to Scenario 9-9, what is the critical value

Answers

Answer 1

Answer:

Step-by-step explanation:

To test the hypothesis is the mean SAT score is less than 1520 at 5% significance level

The nul hypothesis is

[tex]H_0; \mu \geq 1520[/tex]

The alternative hypothesis is

[tex]H_0 ; \mu\leq 1520[/tex]

The test statistic is

[tex]t=\frac{\bar x- \mu}{(\frac{s}{\sqrt{n} } )}[/tex]

[tex]t= \frac{1501-1520}{(\frac{53}{\sqrt{20} } )} \\\\=-1.603[/tex]

The t - test statistics is -1.603

The t - critical value is,

The small size is small and left tail test.

Look in the column headed [tex]\alpha = 0.05[/tex] and the row headed in the t - distribution table by using degree of freedom is,

d.f = n - 1

= 20 - 1

= 19

The t - critical value is -1.729

The conclusion is that the t value corresponds to sample statistics is not fall in the critical region, so the null hypothesis is not rejected at 5% level of significance.

there is insignificance evidence ti indicate that the mean SAT score is less than 1520. The result is not statistically significant

Answer 2

Answer:

Critical value = -1.729

Step by Step explanation:

Given:

n = 20

X' = 1501

Standard deviation = 53

Mean, u = 1520

Level of significance, a = 0.05

The null and alternative hypotheses:

H0 : u = 1520

H1 : u < 1520

This is a lower tailed test.

Degrees of freedom, df = 20 - 1 = 19

For critical value:

[tex]t critical = - t_a, _d_f [/tex]

From t table df = 19, one tailed

[tex]t critical = -t _0._0_5, _1_9 = -1.729[/tex]

Critical value = -1.729

Decision: Reject null hypothesis H0, if test statistic Z, is less than critical value.

Test statistic Z =

[tex] Z = \frac{X' - u}{\sigma / \sqrt{n}} [/tex]

[tex] Z = \frac{1501 - 1520}{53/ \sqrt{20}}= -1.603[/tex]

Z = -1.603

For p-value:

From excel,

P(t< -1.603) = t.dist( -1.603, 19, 1)

= 0.06269

≈ 0.0627

P value = 0.0627

Since test statistic Z, -1.603, is greater than critical value, -1.729, we fail to reject the null hypothesis H0.

There is not enough statistical evidence to conclude that mean is less than 1520.


Related Questions

Tasty Things Bakery recently sold 20 desserts, including 8 brownies. Considering this data, how many of the next 5 desserts sold should you expect to be brownies?

Answers

Answer:

About 2 of their next 5 deserts sold would be brownies.

Let's represent this by fractions. If 8 out of the 20 desserts they sold were brownies, that would make the fraction 8/20 represent how many brownies were sold.

Now if you reduce this fraction, you get 2/5, which tells about how many brownies will be sold in the next 5 brownies judging by the other data.

Using the letter x for any unknown number. i think of a number i add one and then double it

Answers

Answer:

2(x+1) or 2x+2

What is the correct order to represent 92,232

Answers

Wdym, do you mean like 90,000+ 2,000+200+30+2

A company wants to decrease their energy use by 10%. If their electric bill is currently $1,500 a month, what will their bill be if they are successful? Give your answer accurate to at least the nearest dollar.

Answers

Answer:

  $1350

Step-by-step explanation:

Apparently, we're to assume that the bill is proportional to the energy usage. Then reducing energy by 10% would reduce the bill by 10%.

10% of the bill is 0.1 × $1500 = $150.

If the bill is reduced by $150, it becomes ...

  $1500 -150 = $1350

If they are successful, their bill will be $1350.

_____

In general, utility bills have a number of fixed charges or fees that are not proportional to the quantity of utility used. Too, they can have graduated rates that make them non-proportional.

Figuring 90% of some arbitrary number might be an interesting math exercise, but it has no relation to the world of utility billing for a 10% change in usage.


Which decimal is equivalent to 2680?

Answers

Answer:

0.5361

Step-by-step explanation:

Hope this helps :)

Answer:

0.325

Step-by-step explanation:

Divide 26 by 80

are repeating decimals rational or irrational? explain your reasoning in detail and use examples to prove your response

Answers

Answer:

Rational

Step-by-step explanation:

Because the decimal is repeating like 3.33333333 repeating it would be rational because it can be predicted that the number after it would be 3. If the answer was .5647395043794 with more number after it then it wouldn't be able to be determined and would be irrational.

PLEASEE HELPP MEEE WITH NUMBERSSS 6 AND 7
ILL MARKK U BRAINLIEST FOR UR EFFORT FOR THE CORRECT ANSWER!!!!!!!!!!

Answers

Answer:

6.)66 degrees

7.)20 degrees

Step-by-step explanation:

Step-by-step explanation:

Angle 114 and angle 3 are supplementary, meaning that they can be added to get 180 degrees

If you subtract 114 from 180 you get 66 degrees

Angle D and Angle C are both complimentary, meaning that if you add them together you get 90 degrees

If you subtract 70 from 90 you get 20

Please help me and I’ll Try to help you

Answers

Answer:

12/35

Step-by-step explanation:

What is the mean and standard deviation of the adult values in the table below?

Number Fish length

to the nearest inch Description
1 12 Adult
2 5 Juvenile
3 3 Juvenile
4 6 Adult
5 8 Adult
6 2 Juvenile
7 10 Adult
8 9 Juvenile
9 4 Juvenile
10 4 Juvenile
Mean = 2.6, Standard Deviation = 9
Mean = 4.3, Standard Deviation = 12
Mean = 12, Standard Deviation = 4.3
Mean = 9, Standard Deviation = 2.6

Answers

Answer: Mean = 9, Standard Deviation = 2.6

Answer:

The correct answer is:

Mean =9, standard deviation =2.6

Step-by-step explanation:

I got it right.

Kelly can tune 4 cars in 3 hours. If we assume he works at a constant rate, we can describe the situation using a function. a) Write the function that represents Kelly’s constant rate of work.
Your answer

Answers

Answer:

Rate = (4C)cars/3(H)hrs

Step-by-step explanation:

Kelly can tune 4 cars in 3 hours.

The rate at which he dies work = 4/3

Thanks rate at which he tunes cars = 4/3 cars/hr

The expression of the above formula for C fraction of 4 cars and H fraction of 3 hours will be 4(C)/3(H)

Rate = (4C)cars/3(H)hrs

Consider the graph of the quadratic function y = 2x2 - 4x
+ 2.
How many zeros does the function have?
ob
6
2
-2
2
-2

Answers

Answer:2

Step-by-step explanation:

If Tim draws two cards at random from a standard deck of cards without replacement, which expression represents the probability that Tim draws two aces?
1. 4/52 * 4/52
2. 4/52 * 4/51
3. 4/52 * 3/51
4. 4/52 * 3/52

Answers

Answer: B) 4/52 * 3/51

Step-by-step explanation:

the probability of drawing the first ace is 4/52 bc there are 4 aces and 52 cards. the probability of drawing the second ace is 3/51 bc there are now three aces ( bc we removed one in the first step) and there are now 51 cards (bc we removed a card in the first step and there is no replacement). combine the probabilities with multiplication because it’s a multistage event

What is 192837288-19929

Answers

Step-by-step explanation:

The answer is to your question is 192817359

192837288 - 19929 =

Answer: 192,817,359

the fire hydrant sits 72 feet from the base of a 125-foot buiding. Find the ANGLE OF ELEVATION from the fire hydrant to the top of the building. *

Answers

Answer:

  60°

Step-by-step explanation:

The mnemonic SOH CAH TOA reminds you of the relationship between angles and sides in a right triangle. Here, we're given the side Adjacent and the side Opposite the angle of interest. This makes it appropriate to choose the relation ...

  Tan = Opposite/Adjacent

For our angle of elevation α, this means ...

  tan(α) = 125/72

  α = arctan(125/72) = 60.058°

  α ≈ 60°

The angle of elevation is about 60°.

Choose the best option.
1.(101), in base 10 is equal to:
a)10
b)1
c)2
d)5​

Answers

Answer:5

Step-by-step explanation:(1×2^2)+(0×2^1)+(1×2^0)=

1×4+0×2+1×1=

4+1=

5

Find x in DEF

A. 6
B. 6 (square root 2)
C. 6 (square root 3)
D. 12​

Answers

Answer:

B. 6√2

Step-by-step explanation:

We can use the Pythagorean Theorem to solve this out. The Pythagorean Theorem states that for any right triangle with the shortest sides (called legs) as a and b and the longest side (called the hypotenuse) as c:

a² + b² = c²

Here, a = b = 6, so:

6² + 6² = c²

36 + 36 = c²

72 = c²

c = √72 = 6√2

Now, we see the answer is B.

However, there's a trick to solving these kinds of problems. Notice that DEF is both an isosceles triangle and a right triangle. We call these 45-45-90 triangles because those are the angles of the triangle.

One characteristic of these types of triangles is that their leg to leg to hypotenuse ratio is 1 : 1 : √2, always. We could apply that here. We see that the legs are 6, so we could find the hypotenuse simply by multiplying 6 by √2, and we would get 6√2, which is exactly the value we obtained above.

Thus, the answer is B.

What’s the correct answer for this?

Answers

The equation of the circle:

[tex](x-x_0)^2+(y-y_0)^2=R^2[/tex]

[tex]x_0=-6;y_0=-3; R=12,so\\(x-(-6))^2+(y-(-3))^2=12^2\\(x+6)^2+(y+3)^2=144[/tex]

Answer: [tex](x+6)^2+(y+3)^2=144[/tex]

A game consists of randomly choosing a bag (labelled 1, 2 or 3) out of a choice
of 100, and then again randomly, picking a ball (red or black) from it.
Each bag has the same total number of balls (10).
Bag options
Ball options
a) Complete the tree diagram.
0.6 Red
b) Work out the probability that a player
will select a red ball.
0.4 Black
0.35
0.44
0.2
Red
0.45
2
0.8
Black
c) The same player is going to play the
game 200 times consecutively.
How many black balls should he
expect to pick?
0.2
0.7
Red
3
I
+
0.3
Black

Answers

I think answer is 80 please give me brainlest I hope this helps let me know if it’s correct or not

What is the approximate area of a circle with a radius of 11 m?
O A. 190 m2
O B. 69 m2
O C. 34.5 m2
O D. 380 m2

Answers

Hello!

Answer:

[tex]\boxed{ \bf The~approximate~area~of~the~circle~is~D.~380~m^2}[/tex]

___________________________________________

Explanation:

We must use a certain formula to find the area of a circle.

A = πr²

Let's plug in the radius.

A = π × 11²

A = π × 121

A = 380

Please help................

Answers

[tex]184.5 \: ft {?}^{2} [/tex]

ASAP! GIVING BRAINLIEST! Please read the question THEN answer correctly! No guessing. Show your work or give an explaination.

Answers

Answer:

B. Yes, because it passes the vertical line test.

Step-by-step explanation:

Let's review why the other answers are incorrect.

First, A would not be correct since a curved line doesn't necessarily indicate that it is a function, however, it is a non-linear function since it's not a straight line but rather a curved line as said. Now, you might be wondering why exactly A would not be correct even if it is a non-linear function, the reason is because most of time, you are asked to find and determine if a graph is a function or not using the vertical line test.

Second, C would not be correct since it is saying that a function has to be a straight line, but as we've covered that above, in which a function does not have to be linear and can be non-linear which means it's a curved line. Thus, C is not correct as non-linear functions exist.

Third, D would not be correct because this graph actually does pass the vertical line test. In order for the graph to fail the vertical line test, it has to touch the graph in the same x points. This graph passes the vertical line test, since the x coordinates haven't repeated yet, however in some cases, the direction of the line may suddenly change and touch upon the same x points. But, in theory, this line would be starting from the origin and heading to infinity with it's curvature.

Lastly, the reason why B is correct is due to it passing the vertical line test. Again, we already covered this in the 3rd reason but I must make it clear that, this is a function since it passes the vertical line test.

Answer:

B

Step-by-step explanation:

We can eliminate options A and C because in order to be a function, a graph doesn't have to be curved or a straight line. For examlpe, a straight line isn't curved, and a parabola isn't a straight line, but they are still functions. This leaves us with options B and D, which both pertain to the vertical line test. If we conduct this test, we will find that no vertical line intersects the graph and 2 points. Therefore, it passes the vertical line test, and is a function. Hope this helps!

A) Find the difference between3y minutes and 25y second,giving your answer in second.
B) find the sum of 50(3z- 2) minutes and4(z+1) hour,giving your answer in second.
Pls tell answers of both question

Answers

Answer:

a. 3 mintes = 180 seconds

Answer:

155ysec ; 23400z+ 8400 secs

Step-by-step explanation:

3y mins = 3* 60=180y sec

3y mins - 25y sec= 180y sec - 25y= 155y sec

155ysec

From B

50(3z-2)min = 50 * 60 (3z-2) sec

= 3000(3z-2)=9000z-6000

4 (z + 1) hours =4*3600(z+1) =14400z + 14400z

Adding both expression we have;

9000z+14400z-6000+14400=23400z+ 8400 secs

23400z+ 8400 secs

is this a example of a literal equation 4x+7=22

Answers

Answer:

yes

Step-by-step explanation:

A literal equation is an equation where variables represent known values.

Please help ASAP!! Will get brainliest

Answers

Answer:

x=7

Step-by-step explanation:

Answer:

7

Step-by-step explanation:

12 bars --- 2 boxes

42 bars --- x boxes

x = 42*2/12 = 7

It is claimed that the expected length of time some computer part may work before requiring a reboot is 26 days. In order to examine this claim, 80 identical parts are set to work. Assume that the distribution of the length of time the part can work (in days) is Exponential. The 80% percentile of the distribution of the average is of the form E(X) ± c, where E(X) is the expectation of the sample average. The value of c is ________. (You are asked to apply the Normal approximation to the distribution of the average of the 80 parts that are examined. The answer may be rounded up to 3 decimal places of the actual value.)

Answers

Answer:

3.012  

Step-by-step explanation:

Let use x to represent the length of time  some computer part may work

where ; we have a sample of  size n = 80

Say [tex]X_1, X_2, ... X_{80[/tex]

[tex]X_i[/tex]  [tex]\approx[/tex] [tex]exp (\lambda)[/tex]   where ( λ =26 days)

[tex]E( \bar X) = \frac{1}{n} \sum \limits^n_{i=1} E( {x_i})= 26[/tex]

[tex]V(\bar X) = \frac{1}{n^2} \sum \limits ^n_{i=1} U(X_i) = \frac{(26)^L}{n}[/tex]

So find [tex]\bar X 's[/tex] distribution using the Normal approximation.

[tex]\bar X \approx N (26, \frac{(26)}{n}^L)[/tex]

[tex]Z = \dfrac{\bar {X} - 26}{\frac{26}{\sqrt n}} \approx N (0,1)[/tex]

However, let's determine c such that:

[tex]P (-c \leq \bar x \leq c) = 0.8 \\ \\ P ( \dfrac{-c-26}{\frac{26}{\sqrt n}} \leq \dfrac{\bar x -26 }{\frac{26}{n} } \leq \dfrac{c-26}{\frac{26}{\sqrt n}}) =0.8[/tex]

[tex]P ( \dfrac{-c-26}{\frac{26}{\sqrt n}} \leq Z \leq \dfrac{c-26}{\frac{26}{\sqrt n}}) =0.8[/tex]

where; [tex]Z \approx N (0,1)[/tex]

[tex]P ( Z > \dfrac{c-26}{\frac{26}{\sqrt n}}) =0.15 = P ( Z < \dfrac{-c-26}{\frac{26}{\sqrt n}})[/tex]

[tex]\dfrac{c-26}{\frac{26}{\sqrt n}}= 1.036[/tex]

[tex]c= 26+\frac{26}{\sqrt 80}}* 1.036[/tex]

c = 29.0115

Given that :

The 80% percentile of the distribution of the average is of the form

E(X) + c

Then;

29.0115-26 = 3.0115

3.012    (to 3 decimal place)

What is the solution to the equation 4x - 6 =
10x - 3?
а
x = 1/2
b
x = -2
C
x = 2
d
x = -1/2

Answers

Answer:

d

Step-by-step explanation:

did da math

4X - 6 = 10X - 3

First you need to group:

-6 + 3 = 10X - 4x
-3 = 6x
-3 / 6 = x
-1/2 = x

So the options are wrong because -1/2 is not one of the options

emily is making a histogram for the data 12 24 56 7 34 75 34 86 34 78 and 96, which is the most appropriate first interval?

A. 0-5

B. 0-10

C. 0-50

D. 0-100

Answers

Answer:

Option B. is correct

Step-by-step explanation:

Given:

Data: 12 24 56 7 34 75 34 86 34 78 and 96

To find: the most appropriate first interval

Solution:

A histogram is a pictorial representation to display frequency data using rectangular bars.

In histogram, each bar is for a range of data.

For the given data, options A. is not appropriate as the least value given in the data is 7.

Option C. is not appropriate as then the data falls under just two intervals only.

Option D. is not appropriate as then the data falls under just one interval only.

Option B. is the most appropriate first interval

Researchers surveyed 1,000 randomly selected adults in the U.S. A statistically significant, strong positive correlation was found between income level and the number of containers of recycling they typically collect in a week.
1. Please select the best interpretation of this result.
Group of answer choices:
O This result indicates that earning more money influences people to recycle more than people who earn less money.
O We can not conclude whether earning more money causes more recycling among U.S. adults because this type of design does not allow us to infer causation.
O This sample is too small to draw any conclusions about the relationship between income level and amount of recycling for adults in the U.S.

Answers

Answer:

Null hypothesis: [tex]\rho =0[/tex]

Alternative hypothesis: [tex]\rho \neq 0[/tex]

The statistic to check the hypothesis is given by:

[tex]t=\frac{r \sqrt{n-2}}{\sqrt{1-r^2}}[/tex]

And is distributed with n-2 degreed of freedom. df=n-2[/tex]

For this case we got a significant result that means that the real correlation coefficient is different from 0 . And for this case the best interpretation would be:

This result indicates that earning more money influences people to recycle more than people who earn less money

Step-by-step explanation:

The correlation coeffcient is given by this formula:

[tex]r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}[/tex]  

For this case we know that this value of r is positive and represent a string correlation between income level and the number of containers of recycling

In order to test the hypothesis if the correlation coefficient it's significant we have the following hypothesis:

Null hypothesis: [tex]\rho =0[/tex]

Alternative hypothesis: [tex]\rho \neq 0[/tex]

The statistic to check the hypothesis is given by:

[tex]t=\frac{r \sqrt{n-2}}{\sqrt{1-r^2}}[/tex]

And is distributed with n-2 degreed of freedom. df=n-2[/tex]

For this case we got a significant result that means that the real correlation coefficient is different from 0 . And for this case the best interpretation would be:

This result indicates that earning more money influences people to recycle more than people who earn less money

The dimensions of a rectangle are x+4 and 3x-1. Write an expression to represent the area of the rectangle.

Answers

Step-by-step explanation:

Step 1:  Multiply them together to get the area

[tex]A = L * W[/tex]

[tex]A = (x + 4)(3x - 1)[/tex]

[tex]A = (x * 3x) + (x * -1) + (4 * 3x) + (4 * -1)[/tex]

[tex]A = 3x^2 - x + 12x - 4[/tex]

[tex]A = 3x^2 + 11x - 4[/tex]

Answer:  [tex]A = 3x^2 + 11x - 4[/tex]

Answer:

3x² + 11x - 4

Step-by-step explanation:

Area = length × width

= (x+4)(3x-1)

= 3x² + 12x - x - 4

= 3x² + 11x - 4

a. Find the first four nonzero terms of the Maclaurin series for the given function. b. Write the power series using summation notation. c. Determine the interval of convergence of the series. ​f(x)equals​(4plusxsquared​)Superscript negative 1 a. The first nonzero term of the Maclaurin series is nothing. The second nonzero term of the Maclaurin series is nothing. The third nonzero term of the Maclaurin series is nothing. The fourth nonzero term of the Maclaurin series is nothing. b. Write the power series using summation notation. Choose the correct answer below. A. Summation from k equals 0 to infinity minus StartFraction 1 Over 4 Superscript k plus 1 EndFraction x Superscript 2 k B. Summation from k equals 0 to infinity StartFraction 1 Over 4 Superscript k plus 1 EndFraction x Superscript k C. Summation from k equals 0 to infinity StartFraction (negative 1 )Superscript k Over 4 Superscript k EndFraction x Superscript k D. Summation from k equals 0 to infinity StartFraction (negative 1 )Superscript k Over (4 )Superscript k plus 1 EndFraction x Superscript 2 k

Answers

Answer:

Check the explanation

Step-by-step explanation:

Kindly check the attached image below to see the step by step explanation to the question above.

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