A six-week fitness program was designed to decrease the time it takes retired individuals to walk one mile. At the beginning of the program, 20 randomly selected retired individuals were invited to participate, and their times to walk a mile were recorded. After the six-week program, their times to walk a mile were again recorded. Most participants saw little to no improvement in their times to walk one mile; however, a few participants saw drastic improvements in their times to walk one mile. The program director would like to perform a hypothesis test to determine if the program reduces the mean time for retired individuals to walk a mile. Which of the following statements is true?

a. Because there are 40 observations in total, the sample size is large enough to assume that the sampling distribution of the sample mean differences is approximately normal.
b. Because the walk times before and after the program are paired, a hypothesis test is not appropriate.
c. The sampling distribution of sample means can be assumed to be approximately normal because the distribution of the sample data is not skewed.
d. Because the sample size of 20 is less than 30 and the improvements in walk times in the sample data appear to be skewed, the distribution of sample means should not be assumed to be approximately normal.
e. Because the program recruited only retired individuals, the distribution of sample means should not be assumed to be approximately normal.

Answers

Answer 1

Answer:

c. The sampling distribution of the sample means can be assumed to be approximately normal because the distribution of the sample data is not skewed

Step-by-step explanation:

From the given data, we have;

The category of the sample = Retired individuals

The number of participants in the sample = 20

The duration of program = six-weeks

The improvement seen by most participants = Little to no improvement

The improvement seen by few participants = Drastic improvement

Therefore, given that the participants are randomly selected and the majority of the participants make the same observation of improvement in the time to walk a mile, we have that, the majority of the outcomes show little difference in walk times after the program, therefore, the distribution of the sample data is not skewed and can be assumed to be approximately normal


Related Questions

Consider the expression 40+24 . Find the greatest common factor of the two numbers and use the distributive property to rewrite the expression

Answers

Hi there!

[tex]\large\boxed{8(5+3)}}[/tex]

The greatest common factor of 40 and 24 is 8.

8 goes into 40 5 times:

8 goes into 24 3 times.

We can rewrite this expression for distribution using the amount of times 8 goes into both numbers:

8(5 + 3)

Using this, we get:

8(5) + 8(3) = 40 + 24.

Each of 200 subjects were shown a proposed commercial and asked to identify the marketed product 5 minutes after the viewing. A​ 95% confidence interval was​ calculated, but the client indicated that the resultant margin of error is too large and must be​ one-fourth its current size. How large does the new sample need to​ be?

Answers

Answer:

Step-by-step explanation:

first off we need to know the original sample size and if it is in there then im just cant see it

Which inequality is shown in this graph?
(0, 3)
5
(2, -3)

Answers

Answer:

It would be A

I think I forgot I didn't this like 2 weeks ago

please help guys asap

Answers

Answer:

28 i think

Step-by-step explanation:

Then determine whether the relation is discrete or continuous?

Answers

Answer:

Can you please include the complete question?

Step-by-step explanation:

Emma is choosing a weekly meeting time. She hopes to have two different
managers attend on a regular basis. The table shows the probabilities that
the managers can attend on the days she is proposing.

Assuming that manager A's availability is independent of manager B's
availability, which day should Emma choose to maximize the probability that
both managers will be available?
A. Monday. The probability that both managers will be available is
0.94.
B. Monday. The probability that both managers will be available is
0.67.
C. Wednesday. The probability that both managers will be available is
0.91.
D. Wednesday. The probability that both managers will be available is
0.71.

Answers

Answer:

Probability that both managers can attend:

Monday- 0.73x0.94 = 0.69

Tuesday- 0.78 x 0.91 = 0.71

So,  d is correct.

Let me know if this helps!

The day Wednesday choose to maximize the probability that both managers will be available. The probability that both managers will be available is 0.71.

What is the probability?

Probability refers to a possibility that deals with the occurrence of random events.

The probability of all the events occurring need to be 1.

The formula of probability can be defined as the ratio of a number of favorable outcomes to the total number of outcomes.

P(E) = Number of favorable outcomes / total number of outcomes

Probability that both managers can attend, consider that manager A's availability is independent of manager B's availability,

Monday;

0.73x0.94 = 0.69

Tuesday;

0.78 x 0.91 = 0.71

So, the option d is correct.

Learn more about probability here;

https://brainly.com/question/9326835

#SPJ7

Find the exact value under the given conditions.

Answers

Answer:
I think is B

Omar’s tank is 3/10 full. After he buys 11 gallons of gas, it is 4/5 full. How many gallons can Omar’s tank hold?

Answers

Answer:

22 gallons.

Step-by-step explanation:

11 gallons took you from 3/10 to 4/5 (same as 8/10).

so the 11 gallons was 5/10- or 1/2 the tank.

if 11 gallons =half a tank, then a full tank is 22 gallons

Will mark brainliest!
What is the value of u?

Answers

Answer:

u=32

Step-by-step explanation:

Hey There!

Those are a pair of complementary angles we can tell because it has a square at the angle.

When angles are complementary they add up to 90

So given one angle we subtract that by 90 to find the missing angle

90-58=32

therefore u = 32

-3 multiplied by 8.2

Answers

Answer:

-24.6

Step-by-step explanation:

-3*8.2= -24.6

The answer is -24.6.
Have a nice day

Find the measure of an angle that is positive and less than 360° in standard position for each reference angle. 68° in quadrant II: 75° in quadrant IV: 22° in quadrant III:​

Answers

Answer:

Step-by-step explanation:

Reference angle for 68° in QII = 180°-68° = 112°

Reference angle for 75° in QIV = 360°-75° = 285°

Find the measure of CD in parallelogram ABCD .

Answers

Answer:

Picture would be appreciated.

Selma went shopping and bought identical sweaters for each of 3 friends. If she spent $42, what was the cost of each sweater? Include your equation with your answer.

Answers

Answer:

14 dollars

Step-by-step explanation:

42 / 3 = x amount of dollars

14 = x

so every one sweater costs 14 dollars

Pls, help solve this asap..

Answers

Answer:

the answer is 8

Step-by-step explanation:

3(8^2) + 1

8^2 = 64

64 x 3 = 192

192 +1 =193

Hope u help me pls I love u

Answers

Answer:c= a +b

Step-by-step explanation:

An engine operating on Dual cycle has a compression ratio of 12. The pressure and temperature at the start of adiabatic compression is 100 KPa. and 37 degree Centigrade. The peak pressure of the cycle is not no exceed 8000 KPa. and the heat supplied to the cycle is 2000 KJ per Kg. of air. Determine the cycle thermal efficiency

Answers

I am not sure but I hope you have a good day good luck

Motorola used the normal distribution to determine the probability of defects and the number of defects expected in a production process. Assume a production process produces items with a mean weight of 11 ounces. a. The process standard deviation is .20 ounces, and the process control is set at plus or minus standard deviations. Units with weights less than or greater than ounces will be classified as defects. What is the probability of a defect (to 4 decimals)

Answers

The question supplied is incomplete :

The x parameters aren't given ; "Units with weights less than or greater than ounces will be classified as defects"

Assume the unit weights Given are ;

Units with weights less than 10.8 or greater than 11.2 ounces will be classified as defects

Just follow the procedure in the solution for any value of unit weight interval given.

Answer:

0.3173

Step-by-step explanation:

Mean weight, m = 11 ounces

Standard deviation, s = 0.2 ounces

Find the Zscore for each unit weight :

Z = (x - mean) / standard deviation

P(x < 10.8) :

Z = (10.8 - 11) / 0.2 = - 1

P(Z < - 1) = 0.15866

P(x > 11.2) :

Z = (11.2 - 11) / 0.2 = 1

P(Z > 1) = 0.84134

P(x < 11.2) - P(x < 10.8) = 1 - (P(Z < 1) - P(Z < - 1)) = 1 - 1 - (0.84134 - 0.15866) = 1 - 0.68268 = 0.31732

Hence, Probability of a defect is 0.3173

For a sparkling apple juice recipe with two ingredients, Timmy uses 3 1/4 cups of apple juice and 4 2/3 cups of lemon-lime soda. How much juice is he making?

Answers

Answer:

anlamiyorum ne diyorsun

7 11/12 i think but i’m pretty sure it’s right

Q. You are employed at a grain processing
plant that sells cornmeal for $1.28 per pound.
If a sack of cornmeal weighs 4 pounds 12
ounces, how much does it cost?
A. $6.08
B. $4.95
C. $5.12
D. $6.40

Answers

Answer:

A (6.08)

Step-by-step explanation:

Hi! Here is how you would handle this problem :D

First, multiply 1.28 (money per pound) by 4 (whole pounds), you would get 5.12. Now be careful, because there is one more step! There are 16 ounces in a pound, so 12/16 would equal to 3/4 (75%). Multiply 1.28 by .75 to find out how much you would pay for those 12 ounces. Lastly, add 5.12 and .96 (that comes from 1.28 times .75), and you get 6.08! Hope this helped, and please leave me a brainly if you can!

the number y divided by 100 y. ?

Answers

Answer:

1/100

Step-by-step explanation:

Please help:( I’m stuck on this problem

Answers

Answer:

x=33

Step-by-step explanation:

If you didn't know all of the angles in a triangle add up to equal 180

We are given to angles, 90 (the square indicates that its a right angle which is equal to 90) and 57

So to find the missing anlge we subtract the given angles from 180

180-90=90

90-57=33

therefore x=33

NEED HELP ON THIS ASAP

Answers

Answer:

34

Step-by-step explanation:

Scan QR code and it takes to homework so u can answer question i will give brainliest to correct answer please answer correct

Answers

im just gonna take the points for falling for that.

What is the volume of the prism?
2 cm
3cm
11 cm PLS HURRY

Answers

Answer:

66

Step-by-step explanation:

multiply everything together

Problem 8
Tameeka's sunflower is currently 58 millimeters. She
notices that the sunflower grows 8 millimeters each day.
Write an expression to represent this situation.

Answers

Answer:

Step-by-step explanation:

if tameekas sunflower is 58 millmetters and grows 8 millmeters a day then in the 7 days she grew it,  it has grown 58 millmeters.

True or False? The chart below shows a linear relationship function.
X -1 0 4
Y 1 3 11
T. True, this is linear F. False, this is not linear

Answers

Answer:

False

Step-by-step explanation:

A manufacturer orders lots of steel rods from a supplier (each lot consists of thousands of rods). Assume that the mean length of the rods in each lot is 4 meters and standard deviation is 0.04 meter. The quality manager accepts a lot if the mean length of the randomly selected sample of 64 rods from that lot is at least 4.005 meters, otherwise the lot is returned to the supplier. a) What percentage of the lots received by the manufacturer will be returned to the supplier

Answers

Answer:

84.13% of the lots received by the manufacturer will be returned to the supplier

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Assume that the mean length of the rods in each lot is 4 meters and standard deviation is 0.04 meter.

This means that [tex]\mu = 4, \sigma = 0.04[/tex]

Sample of 64:

This means that [tex]n = 64, s = \frac{0.04}{\sqrt{64}} = 0.005[/tex]

a) What percentage of the lots received by the manufacturer will be returned to the supplier

The proportion is the pvalue of Z when X = 4.005. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{4.005 - 4}{0.005}[/tex]

[tex]Z = 1[/tex]

[tex]Z = 1[/tex] has a pvalue of 0.8413

0.8413*100% = 84.13%

84.13% of the lots received by the manufacturer will be returned to the supplier

For the most recent year available, the mean annual cost to attend a private university in the United States was $50,900. Assume the distribution of annual costs follows the normal probability distribution and the standard deviation is $4,500. Ninety-five percent of all students at private universities pay less than what amount

Answers

Answer:

95% of all students at private universities pay less than $58,302.5.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Mean of $50,900, standard deviation of $4,500

This means that [tex]\mu = 50900, \sigma = 4500[/tex]

Ninety-five percent of all students at private universities pay less than what amount?

Pay less than the 95th percentile, and the amount is given by X when Z has a pvalue of 0.95, so X when Z = 1.645.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.645 = \frac{X - 50900}{4500}[/tex]

[tex]X - 50900 = 1.645*4500[/tex]

[tex]X = 58302.5[/tex]

95% of all students at private universities pay less than $58,302.5.

Which values are solutions to × > 7? A. × = 11 and × = 1 B. × = 0 and × = 8 C. × = 8 and × = 11 D. × = -8 and × = 0

Answers

Answer:

C

Step-by-step explanation:

Blake is going to invest $79,000 and leave it in an account for 9 years. Assuming the interest is compounded monthly, what interest rate, to the nearest tenth of a percent, would be required in order for Blake to end up with $96,000?

Answers

Answer:

r =2.2%

Step-by-step explanation:

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