Question

(Assume that the samples are randomly selected and independent.)

Sample statistics: x 1 = 36, n 1 = 64 and x 2 = 47, n 2 = 71;

Construct a 95% confidence interval for the difference between population proportions p1 – p2

Select one:

0.368 < p1 – p2 < 0.757

-0.263 < p1 – p2 < 0.064

-0.294 < p1 – p2 < 0.757

0.399 < p1 – p2 < 0.726

2.

Two independent samples are randomly selected and come from populations that are normal. The sample statistics are given below:

n1 = 47 n2 = 52

1 = 24.2 2 = 18.7

s1 = 5.0 s2 = 5.6

Find the standardized test statistic t to test the hypothesis that μ1 = μ2. Round your answer to three decimal places.

3.

A random sampling of 60 pitchers from the National League and 74 pitchers from the American League showed that 38 National and 36 American League pitchers had E.R.A's below 3.5.

Find the test statistic that would be used to test the claim that the proportion of the NL pitchers with E.R.A. below 3.5 is higher than the proportion of the AL pitchers with similar stats.

Round your answer to three decimal places.

Answer 1