statistics

 first six questions.

1.      Construct the indicated confidence interval for the difference between population proportion. Assume that the samples are independent and that they have been randomly selected. In a random sample of 300 women, 45% favored stricter gun control legislation. In a random sample of 200 men, 25% favored stricter gun control legislation. The claim is that women are more likely to support stricter gun control legislation. Construct a 98% confidence interval for the difference between the population proportions.

2 points   

QUESTION 2

1.      Find the number of successes x suggested by the given statement.  A computer manufacturer randomly selects 2680 of its computers for quality assurance and finds that 1.98% of these computers are found to be defective.

1 points   

QUESTION 3

1.      Assume that you plan to use a significance level of α = 0.05 to test the claim that p1 = p2, use the given sample sizes and numbers of successes to find the P-value for the hypothesis test.n1 = 50                  n2 = 50                  x1 = 8                     x2 = 7

2 points   

QUESTION 4

1.      Assume that you plan to use a significance level of α = 0.05 to test the claim that, Use the given sample sizes and numbers of successes to find the pooled estimate p. Round your answer to the nearest thousandth.n1 = 100                n2 = 100                x1 = 42                   x2 = 45

1 points   

QUESTION 5

1.      A paint manufacturer made a modification to a paint to speed up its drying time. Independent simple random samples of 11 cans of type A (the original paint) and 9 cans of type B (the modified paint) were selected and applied to similar surfaces. The drying times, in hours, were recorded. The summary statistics are as follows. Type A                                 Type Bx1 = 76.3 hrs                        x2= 65.1 hrss1 = 4.5 hrs                          s2= 5.1 hrsn1 = 11                               n2= 9 The following 98% confidence interval was obtained for μ1 - μ2, the difference between the mean drying time for paint cans of type A and the mean drying time for paint cans of type B:  4.90 hrs < μ1 - μ2 < 17.50 hrs What does the confidence interval suggest about the population means?

2 points   

QUESTION 6

1.      Construct the indicated confidence interval for the difference between the two population means. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. Arrival delay times in minutes of two flights between Los Angeles and New York are given below. Use alpha = 0.05.