Solution: Part A: A USA Today article claims
that the proportion of people who believe global warming is a
serious issue is 0.6, but given the number of people you've talked
to about this same issue, you believe it is less than 0.6. The
hypotheses for this test are Null Hypothesis: p ≥ 0.6, Alternative
Hypothesis: p < 0.6. You take a random sample and perform a
hypothesis test, getting a p-value of 0.0831. What is the
appropriate conclusion? Conclude at the 5% level of
significance.
Answer: 5) We did not find enough evidence to say the
proportion of people who believe global warming is a serious issue
is less than 0.6.
Because p-value = 0.0831 is greater than the
significance level = 0.05, we therefore fail to reject the null
hypothesis and conclude that there is not enough evidence to say
the proportion of people who believe global warming is a serious
issue is less than 0.6
Part B: Consumers Energy states that the average electric bill
across the state is $68.76. You want to test the claim that the
average bill amount is actually different from $68.76. The
hypotheses for this situation are as follows: Null Hypothesis: μ =
68.76, Alternative Hypothesis: μ ≠ 68.76. If the true statewide
average bill is $68.76 and the null hypothesis is not rejected, did
a type I, type II, or no error occur?
Answer: 1) No error has occured.
Because we have made correct decision, therefore there
is no error.
Part C: Is there a relationship between car purchases and
political party? You make a tabulation of people who were asked
about the origin of their primary car and their political party
affiliation. To determine if Political Party and Car Origin are
dependent, what are the appropriate hypotheses?
Answer: The correct option is
2) HO: Political Party and Car Origin are not related to
one another.
HA: Political Party and Car Origin are dependent on each
other.
Part D: Suppose that in a certain neighborhood, the cost of a
home is proportional to the size of the home in square feet. If the
regression equation quantifying this relationship is found to be
(cost) = 87.718*(size) + 629.969, what does the slope indicate?
Answer: 1) When size increases by 1 square foot, cost
increases by 87.718 dollars.