Compute the relative frequencies for the data given in the table below:

A	16
B	28
C	33
D	13
Total	90

0.31, 0.14, 0.37, 0.18

0.37, 0.14, 0.31, 0.18

0.16, 0.28, 0.33, 0.13

0.18, 0.31, 0.37, 0.14

Question 2

Scores on Ms. Bond's test have a mean of 70 and a standard deviation of 11. Michelle has a score of 48. Convert Michelle's score to a z-score. (Round to two decimal places if necessary.)

2

41.64

-2

1.33

Question 3

A statistics teacher started class one day by drawing the names of n = 16 students out of a hat and asked them to do as many pushups as they could. The 16 randomly selected students averaged 15.2 pushups per person with a standard deviation of8.5 pushups. Suppose the distribution of the population of number of pushups that can be done is approximately normal.

The 95% confidence interval for the true mean number of pushups that can be done is

10.67to 19.73.

8.56 to 21.44.

5.85 to 24.15.

11.31 to 18.55.

13.15 to 16.83.

Question 4

Consider the following hypotheses:

H0: = 20

Ha: < 20

If the test statistic ist = -2.05, with 33 degrees of freedom, what is the p-value?

(Hint: The Excel function T.DIST is useful for finding p-values for t statistics.)

0.0242

0.9758

0.0484

0.4798

0.5202

Question 5

The following random sample from a population whose values were normally distributed was collected: 10, 8, 11, 11. Calculate the 95% confidence interval for .

Hint: Use Excel to find the sample mean and sample standard deviation.

7.75 to 12.25

8.52 to 10.98

9.75 to 10.75

8.00 to 10.00

Question 6

A manager wishes to predict the annual cost (y) of an automobile based on the number of miles (x) driven. The following model was developed:

y = 1,550 + 0.36x

If a car is driven 20,000 miles, the predicted cost is ____________.

8,750

7,200

5,650

2,270

6,750

Question 7

The following data is to be used to construct a regression model:

X	Y
5	8
7	9
4	12
15	26
12	16
9	13

Use software. The regression equation is _______________.

y = 1.36 + 2.16x

y = 2.16 + 1.36x

y = 0.68 + 0.57x

y = 0.57 + 0.68x

y = 0.57 - 0.68x

Question 8

The below sample data set shows the relationship between two variables.

x	y
10	8.04
8	6.95
13	7.58
9	8.81
11	8.33
14	9.96
6	7.23
4	4.26
12	10.84

What percentage of the variation in the y variable is explained by its linear relationship with x?

79.5%

267%

63%

80%

Question 9

A simple random sample of 11 observations from a population containing 400 female soccer players was taken, and the following values were obtained.

48 53 72 56 63 64 56 76 50 46 73

What is the value of the point estimate of the population mean?

59.7

45.2

94.3

27.6

10.

Question 10

A confidence interval for estimating a population proportion, p, is expressed as (0.46, 0.54). What is the margin of error for this problem?

0.08

0.04

0.50

0.40

0.80