In each of the given Exercises, we have presented a contingency table that gives a cross-classification of a random sample of values for two variables, x, and y, of a population. For each exercise, perform the following tasks.

a. Find the expected frequencies. Note: You will first need to compute the row totals, column totals, and grand total.

b. Determine the value of the chi-square statistic.

c. Decide at the 5% significance level whether the data provide sufficient evidence to conclude that the two variables are associated.

Short Answer

Expert verified

Ans:

(a)

(b) From the MINITAB output, the value of the chi-square statistic is 0.794.

(c) The data do not provide sufficient evidence to conclude that the two-variable are associated at the 5% significance level.

Step by step solution

01

Step 1. Given information.

given,

we have presented a contingency table that gives a cross-classification of a random sample of values for two variables, x, and y, of a population. For each exercise, perform the following tasks.

02

Step 2. (a) Find the expected frequencies by using MINITAB.

MINITAB procedure:
<Step 1> Choose Stat > Tables > Chi-Square test for association.
<Step 2> In Columns containing the table, enter the column of A and B.
<Step 3> In Rows, select y.
<Step 4> Under Statistics, we select the Chi-square test, Display counts in each cell, Display marginal counts and expected cell counts.
<Step 5> Click OK.

03

Step 3. Output:

Chi-Square Test for Association: y, Worksheet columns

04

Step 4. From the MINITAB output, the row totals, column total, and grand total are tabulated given below:

05

Step 5. From the MINITAB output, the expected frequencies are tabulated given below:

06

Step 6. (b) Determine the value of the chi-square statistic.

So, from the MINITAB output, the value of the chi-square statistic is 0.794.

07

Step 7. (c) Check whether or not the data provide sufficient evidence to conclude that the two variables are associated at the 5% significance level.

The hypotheses are given below:

Null hypothesis:

H0 : The two variables are not associated.

Alternative hypothesis:

H1: The two variables are associated.

08

Step 8. Conclusion for the 5% significance level:

From the output, the value of the test statistic is 0.794 and the p-value is 0.373.

Here, the p-value is greater than the level of significance.

That is, p-value(=0.373)>α(=0.05).

Therefore, the null hypothesis is not rejected at the 5% level.

Thus, the data do not provide sufficient evidence that concludes the two-variable are associated at the 5% significance level.

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Most popular questions from this chapter

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US. Hospitals. Refer to Exercise 12.50.


24 or fewer25-7475 or moreTotal
General260158635575403
Psychiatric24242471737
Chronic132226
Tuberculosis0224
Other25177208410
Total310201042606580

a. Determine the conditional distribution of number of beds within each facility type.

b. Does an association exist between facility type and number of beds for U.S. hospitals? Explain your answer.

c. Determine the marginal distribution of number of beds for U.S. hospitals.

d. Construct a segmented bar graph for the conditional distributions and marginal distribution of number of beds. Interpret the graph in light of your answer to part (b),

e. Without doing any further calculations, respond true or false to the following statement and explain your answer. "The conditional distributions of facility type within number-of-beds categories are identical.

f. Determine the marginal distribution of facility type and the conditional distributions of facility type within number-of-beds categories.

g. What percentage of hospitals are general facilities?

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i. What percentage of general facilities have at least 75 beds?

In this exercise, you are to consider two variables, xand ydefined on a hypothetical population. Following are the conditional distributions of the variable ycorresponding to each value of the variablex.
a. Are the variables xandy associated? Explain your answer.
b. Determine the marginal distribution ofy.
c. Can you determine the marginal distribution of x? Explain your answer.

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