Question

1) Based on a sample of 600 people, 33% owned cats

The test statistic is:  (to 2 decimals)

The p-value is:  (to 2 decimals)

2) Based on a sample of 80 men, 30% owned cats
Based on a sample of 60 women, 45% owned cats

The test statistic is:  (to 2 decimals)

The p-value is:  (to 2 decimals)

3) Exercise 6.13 presents the results of a poll evaluating support for the health care public option plan in 2009. 70% of 819 Democrats and 42% of 783 Independents support the public option.


(a) Calculate a 95% confidence interval for the difference between (p_D - p_I) and interpret it in this context. We have already checked conditions for you.
The confidence interval is: ( %,  %) (please round to the nearest percent) Interpret the confidence interval in context:

• 95% of differences in proportions are contained within this interval
• We can be 95% confident that the difference in sample proportions is contained within our interval
• We can be 95% confident that the difference in population proportions is contained within our interval

(b) True or false (Explain): If we had picked a random Democrat and a random Independent at the time of this poll, it is more likely that the Democrat would support the public option than the Independent.

• false
• true

4) To begin answering our original question, test the claim that the proportion of children from the low income group that drew the nickel too large is greater than the proportion of the high income group that drew the nickel too large. Test at the 0.05 significance level.

Recall 28 of 40 children in the low income group drew the nickel too large, and 12 of 35 did in the high income group.

a) If we use LL to denote the low income group and HH to denote the high income group, identify the correct alternative hypothesis.

• H1:pL>pHH1:pL>pH
• H1:μL<μHH1:μL<μH
• H1:pL≠pHH1:pL≠pH
• H1:μL≠μHH1:μL≠μH
• H1:pL<pHH1:pL<pH
• H1:μL>μHH1:μL>μH

b) The test statistic value is:   

c) Using the P-value method, the P-value is:

d) Based on this, we

• Reject H0H0
• Fail to reject H0H0

e) Which means

• There is not sufficient evidence to support the claim
• There is sufficient evidence to warrant rejection of the claim
• The sample data supports the claim
• There is not sufficient evidence to warrant rejection of the claim

Answer 1

1. Incomplete question

2. Incomplete question

3. (a)
The confidence interval is: ( 23%, 33%) (please round to the nearest percent) Interpret the confidence interval in context:

• We can be 95% confident that the difference in population proportions is contained within our interval

(b) True or false (Explain): If we had picked a random Democrat and a random Independent at the time of this poll, it is more likely that the Democrat would support the public option than the Independent.

• true

4.

a) If we use LL to denote the low income group and HH to denote the high income group, identify the correct alternative hypothesis.

• H1:pL>pHH1:pL>pH

b) The test statistic value is: 3.09

c) Using the P-value method, the P-value is: 0.0010

d) Based on this, we

• Reject H0

e) Which means

• The sample data supports the claim