In: Statistics and Probability
5. According to a Pew Research Center nationwide telephone survey
of American adults conducted by phone between March 15 and April
24, 2011, 75% of adults said that college education has become too
expensive for most people and they cannot afford it (Time, May 30,
2011). Suppose that this result is true for the 2011 population of
American adults. In a recent poll of 1600 American adults, 1160
said that college education has become too expensive for most
people and they cannot afford it. Using a 1% significance level,
perform a test of hypothesis to determine whether the current
percentage of American adults who will say that college education
has become too expensive for most people and they cannot afford it
is lower than 75%.
a. Identify the claim and state the H0 and H1.
b. Find the critical value.
c. Calculate the test statistic.
d. Make a decision to reject or fail to reject the H0.
e. Interpret the decision in the context of the original
claim.
6. A food company is planning to market a new type of frozen
yogurt. However, before marketing this yogurt, the company wants to
find what percentage of the people like it. The company’s
management has decided that it will market this yogurt only if at
least 35% of the people like it. The company’s research department
selected a random sample of 400 persons and asked them to taste
this yogurt. Of these 400 persons, 112 said they liked it. Can you
conclude that the company should market this yogurt? Use
α=0.025.
a. Identify the claim and state the H0 and H1.
b. Find the critical value.
c. Calculate the test statistic.
d. e. Make a decision to reject or fail to reject the HInterpret
the decision in the context of the original claim0.