Question

1) Objective: To conduct a hypothesis test for −

The following are weights in pounds for a simple random sample of 20 newborn baby boys and baby girls born in the U.S.

Baby boy birth weights: 6.6,  7.9,  6.4,  7.6,  6.4,  8.1,  7.9,  8.3,  7.3,  8.2 6.7,  6.2,  7.5,  7.8,  7.6,  6.8,  7.9,  8.7,  6.4,  8.4

Baby girl birth weights: 7.3,  7.1,  6.1,  7.4,  6.0,  6.9,  8.2,  7.5,  5.9,  8.1, 7.3,  6.8,  8.1,  6.7,  6.3,  7.2,  6.4,  6.9,  6.2,  8.0

Assume that the birth weights of both populations are roughly normally distributed.  Can you conclude that mean weights are greater for boys born in the U.S. than for girls? Use the P-value method with

Step 1) Check the assumptions

Simple random sample both populations

Independent (different individuals)

Normally distributed (10 individuals <30)

Step 2) Write the null and alternate hypotheses

:

:

Step 3) Draw, label, sketch: test statistic and the region(s) beyond the test statistic

Step 4) P-value =

Step 5) Decision: reject or do not reject

Is P-value ≤ α?		Yes à reject
		No à do not reject

Formal conclusion:

Answer 1