Question

1) A political strategist claims that 55% of voters in Madison County support his candidate. In a poll of 300 randomly selected voters, 147 of them support the strategist's candidate. At = .05, is the political strategist's claim warranted?

a)No, because the test value –2.72 is in the critical region.

b)Yes, because the test value –2.72 is in the noncritical region.

c)No, because the test value –2.09 is in the critical region.

d)Yes, because the test value –1.23 is in the critical region.

2) Science fiction novels average 310 pages in length. The average length of 12 randomly chosen novels written by I. M. Wordy was 365 pages in length with a standard deviation of 35. At  = .05, are Wordy's novels significantly longer than the average science fiction novel?

a)No Yes because the test value is in the rejection region

b)No because the test value is not in the rejection region

c)Yes because the test value is in the rejection region

d)Yes because the test value is not in the rejection region

Answer 1

Here' the answer to the question. please write back in case you've doubts.

1. n = 300, p = .55, pcap = x/n = 147/300 = .49

Test statistic = (pcap-p)/sqrt(p*p'/n) = (.49-.55)/sqrt(.55*.45/300) = -2.09

The critical value is +/- 1.96

Test statistic of -2.09 is less than -1.96. So, answer is :

Answer: c) No, because the test value –2.09 is in the critical region.

2.

n = 12, mean = 310, stdev = 35, x = 365, alpha = .05

Test-statistic = (x-mean)/(stdev/sqrt(n)) = (365-310)/(35/sqrt(12)) = 5.444

Critical value for alpha = .05 is + 1.645

Test-statistic of 5.444 is more than 1.645, so :

Answer is c) Yes, because the test value is in the rejection region