Question 1

Seat Belts 
A study was conducted to determine whether the use of seat belts in vehicles depends on whether or not a child was present in the car.A sample of 1,000 people treated for injuries sustained from vehicle accidents was obtained,and each person was classified according to (1)child present (yes/no)and (2)seat belt usage (worn or not worn)during the accident.The data are shown in the table below.  ​ ​
-{Seat Belts Narrative} Prepare the table of expected values.

Accepted Answer

​

Question 2

A chi-squared goodness-of-fit test is always conducted as a(n):

Accepted Answer

A)  lower-tail test.
B)  upper-tail test.
C)  two-tail test.
D)  All of these choices are true. B

Question 3

Seat Belts 
A study was conducted to determine whether the use of seat belts in vehicles depends on whether or not a child was present in the car.A sample of 1,000 people treated for injuries sustained from vehicle accidents was obtained,and each person was classified according to (1)child present (yes/no)and (2)seat belt usage (worn or not worn)during the accident.The data are shown in the table below.  ​ ​
-{Seat Belts Narrative} Calculate the value of the test statistic.

Accepted Answer

χ² = 26.016

Question 4

The only way the chi-squared test statistic can be zero is if the observed frequencies are all exactly the same as the expected frequencies.

Accepted Answer

A) True 
 B)False

Question 5

The owner of a consumer products company asked a random sample of employees how they felt about the work they were doing.The following table gives a breakdown of their responses by age.Is there sufficient evidence to conclude that the level of job satisfaction is related to age? Use α = .10.

Accepted Answer

The answer of The owner of a consumer products company...

Question 6

If two events A and B are independent,the P(A and B)= P(A)+ P(B).

Accepted Answer

A) True 
 B)False

Question 7

A chi-squared test of a contingency table with 10 degrees of freedom results in a test statistic of 17.894.Using the chi-squared table,the most accurate statement that can be made about the p-value for this test is that .05 < p-value < .10.

Accepted Answer

A) True 
 B)False

Question 8

In the test of a contingency table,the observed cell frequencies must satisfy the rule of 5.

Accepted Answer

A) True 
 B)False

Question 9

The sampling distribution of the test statistic for a goodness-of-fit test with k categories is a:

Accepted Answer

A)  chi-squared distribution with k − 1 degrees of freedom.
B)  normal distribution.
C)  Student t-distribution with k − 1 degrees of freedom.
D)  None of these choices.

Question 10

In the test of a contingency table,the expected cell frequencies must satisfy the rule of 5.

Accepted Answer

A) True 
 B)False

Question 11

Seat Belts 
A study was conducted to determine whether the use of seat belts in vehicles depends on whether or not a child was present in the car.A sample of 1,000 people treated for injuries sustained from vehicle accidents was obtained,and each person was classified according to (1)child present (yes/no)and (2)seat belt usage (worn or not worn)during the accident.The data are shown in the table below.  ​ ​
-{Seat Belts Narrative} State the appropriate null and alternative hypotheses for this experiment.

Accepted Answer

The answer of Seat Belts 
A study was conducted to...

Question 12

The number of degrees of freedom in testing for normality is the:

Accepted Answer

A)  number of intervals used to test the hypothesis minus one.
B)  number of parameters estimated minus one.
C)  number of intervals used to test the hypothesis minus one minus the number of parameters estimated.
D)  None of these choices.

Question 13

If we want to perform a two-tail test for differences between two populations of nominal data with exactly two categories,we can employ either the z-test of p1 − p2,or the chi-squared test of a contingency table.

Accepted Answer

A) True 
 B)False

Question 14

What statistic do we get when we square the value of z?

Accepted Answer

The answer of What statistic do we get when we...

Question 15

Suppose that a random sample of 150 observations was drawn from a population.After calculating the mean and standard deviation,each observation was standardized and the number of observations in each of the intervals below was counted.Can we infer at the 5% significance level that the data were drawn from a normal population?

Accepted Answer

The answer of Suppose that a random sample of 150...

Question 16

A chi-squared distribution is symmetric.

Accepted Answer

A) True 
 B)False

Question 17

A left-tailed area in the chi-squared distribution equals .90.For 10 degrees of freedom the table value equals 15.9871.

Accepted Answer

A) True 
 B)False

Question 18

The rule of five states that in order to conduct the chi-squared goodness-of-fit test,the ____________________ value for each cell must be five or more.

Accepted Answer

The answer of The rule of five states that in...

Question 19

Consider a multinomial experiment with 200 trials,where the outcome of each trial is classified into one of 5 categories.The number of degrees of freedom associated with the chi-squared goodness-of-fit test equals:

Accepted Answer

A)  195
B)  40
C)  5
D)  4

Question 20

The number of ATVs sold by three salespersons over a 3-month period is shown below:  Use the 5% level of significance and test for the independence of salesperson and type of product sold.

Accepted Answer

The answer of The number of ATVs sold by three...

Exam 15: Chi-Squared Tests

A chi-squared goodness-of-fit test is always conducted as a(n) :

The only way the chi-squared test statistic can be zero is if the observed frequencies are all exactly the same as the expected frequencies.

The owner of a consumer products company asked a random sample of employees how they felt about the work they were doing.The following table gives a breakdown of their responses by age.Is there sufficient evidence to conclude that the level of job satisfaction is related to age? Use α = .10.

If two events A and B are independent,the P(A and B)= P(A)+ P(B).

A chi-squared test of a contingency table with 10 degrees of freedom results in a test statistic of 17.894.Using the chi-squared table,the most accurate statement that can be made about the p-value for this test is that .05 < p-value < .10.

In the test of a contingency table,the observed cell frequencies must satisfy the rule of 5.

The sampling distribution of the test statistic for a goodness-of-fit test with k categories is a:

In the test of a contingency table,the expected cell frequencies must satisfy the rule of 5.

The number of degrees of freedom in testing for normality is the:

If we want to perform a two-tail test for differences between two populations of nominal data with exactly two categories,we can employ either the z-test of p₁ − p₂,or the chi-squared test of a contingency table.

What statistic do we get when we square the value of z?

A chi-squared distribution is symmetric.

A left-tailed area in the chi-squared distribution equals .90.For 10 degrees of freedom the table value equals 15.9871.

The rule of five states that in order to conduct the chi-squared goodness-of-fit test,the ____________________ value for each cell must be five or more.

Consider a multinomial experiment with 200 trials,where the outcome of each trial is classified into one of 5 categories.The number of degrees of freedom associated with the chi-squared goodness-of-fit test equals:

The number of ATVs sold by three salespersons over a 3-month period is shown below: Use the 5% level of significance and test for the independence of salesperson and type of product sold.