Homework: Chapter 10 - Means

Question

Question 7, 10.4.7-T
Part 1 of 6
HW Score: 66.67%, 6 of 9 points
Points: 0 of 1
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Part 1
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 14.3
​,
is there evidence that the children have higher​ IQs? Use the alpha equals 0.05

level of significance.
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Part 1
What type of hypothesis test is appropriate to conduct for this​ research?
A.
Hypothesis test on a population proportion
B.
Hypothesis test on a population standard deviation
C.
Hypothesis test on a population mean

Answer 1

C. Hypothesis test on a population mean

Answer 2

Which distribution should be used for this hypothesis​ test?
A.
The normal distribution because the parameter is a​ proportion, p, and the model conditions are satisfied.
B.
The​ chi-square distribution because the parameter is sigma

or sigma
Superscript 2​,
and the model conditions are satisfied.
C.
The normal distribution because the parameter is the​ mean, sigma

is​ known, and the model conditions are satisfied.
D.
The​ Student's t-distribution because the parameter is the​ mean, sigma

is not​ known, and the model conditions are satisfied.

Answer 3

C. The normal distribution because the parameter is the mean, sigma is known, and the model conditions are satisfied.