Question

A psychologist obtains a random sample of

20

mothers in the first trimester of their pregnancy. The mothers are asked to play Mozart in the house at least 30 minutes each day until they give birth. After 5​ years, the child is administered an IQ test. It is known that IQs are normally distributed with a mean of

100.

If the IQs of the

20

children in the study result in a sample mean of

104.2

and sample standard deviation of

15​,

is there evidence that the children have higher​ IQs? Use the

α=0.10

level of significance. Complete parts ​(a) through

​(d).

Answer 1