Question

Listed in the data table are IQ scores for a random sample of subjects with medium lead levels in their blood. Also listed are statistics from a study done of IQ scores for a random sample of subjects with high lead levels. 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. Complete parts​ (a) and​ (b) below. Use a 0.10 significance level for both parts.

Medium Lead Level	High Lead Level
72	n2=11
95
92	x overbar 2=	90.165
85
90	s2=9.964
97
83
9292
102
111
91

A. The test statistic is???

(round 2 decimal places)

B. P-value is???
(round 3 decimal places)

C. State the conclusion for the test.

A.Reject the null hypothesis. There is sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores.

B.Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores.

C.Fail to reject the null hypothesis. There is sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores.

D.Reject the null hypothesis. There is not sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores.

D. Construct a confidence interval suitable for testing the claim that the mean IQ scores for subjects with medium lead levels is higher than the mean for subjects with high lead levels.

_____<μ1-μ2<______??

(round two decimal places)

E.Does the confidence interval support the conclusion of the​ test?

YES/ NO, because the confidence interval contains ZERO/ ONLY NEGATIVE VALUES/ ONLY POSITIVE VALUES.

Answer 1

The level of significance is . The sample sizes are .

Here, the sample means are . The sample standard deviations are .

a)Thus the test statistic is

b) The P-value is

Since , we fail to reject the null hypothesis.

C) The conclusion is

B.Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores

D) The upper confidence level is

E) YES, because the confidence interval contains ZERO.