multiple statistical questions

Question 1

A goodness of fit test is to be performed to see if Web Surfers prefer any of four Web sites (A, B, C and D) more than the other three. A sample of 60 consumers is used. What is the expected frequency for Web site A?

1/4
20
15
10
30

Question 2

A variable contains five categories. It is expected that data are uniformly distributed across these five categories. To test this, a sample of observed data is gathered on this variable resulting in frequencies of 27, 30, 29, 21, and 24. Using ? = .01, the critical value of chi-square is _______.

7.78
15.09
9.24
13.28
15.48

Question 3

A variable contains five categories. It is expected that data are uniformly distributed across these five categories. To test this, a sample of observed data is gathered on this variable resulting in frequencies of 27, 30, 29, 21, and 24. Using ? = .01, the appropriate decision is _______.

reject the null hypothesis that the observed distribution is uniform
reject the null hypothesis that the observed distribution is not uniform
do not reject the null hypothesis that the observed distribution is uniform
do not reject the null hypothesis that the observed distribution is not uniform
do nothing

Question 4

Sami Schmitt believes that number of cars arriving at his Scrub and Shine Car Wash follow a Poisson distribution. He collected a random sample and constructed the following frequency distribution to test his hypothesis.

The observed value of chi-square for this goodness-of-fit test is _____.

0.73
6.72
3.15
7.81
9.87

Question 5

Catherine Chao, Director of Marketing Research, is evaluating consumer acceptance of alternative toothpaste packages. She wonders whether acceptance is influenced by children in the household. Her staff prepared the following contingency table from a random sample of 100 households.

Children in Household

Pre-teenagers
teenagers
none
Preferred Package
Pump
30
20
10

Tube
10
10
20

Using ? = .05, the observed value of chi-square is ______________.

5.28
9.49
13.19
16.79
18.79

Question 6

In the regression equation, y = 75.65 + 0.50x, the slope is _______.

0.50
75.65
1.00
0.00
-0.50

Question 7

In the regression equation, y = 75.65 + 0.50x, the intercept is _______.

0.50
75.65
1.00
0.00
-0.50

Question 8

Consider the following scatter plot and regression line. At x = 17, the residual (error term) is _______.

positive
zero
negative
imaginary
unknown

Question 9

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 15,000 miles, the predicted cost is ____________.

2090
3850
7400
6950
5400

Question 10

The following data is to be used to construct a regression model:
x
5
7
4
15
12
9
y
8
9
12
26
16
13

The value of the slope is ____________.

2.36
2.16
0.68
0.57
1.36