Q 117

In a restaurant, the proportion of people who order coffee with their dinner is 0.9. A simple random sample of 144 patrons of the restaurant is taken.
a.What are the expected value, standard deviation, and shape of the sampling distribution of?
b.What is the random variable in this problem? Define it in words.
c.What is the probability that the proportion of people who will order coffee with their meal is between 0.85 and 0.875?
d.What is the probability that the proportion of people who will order coffee with their meal is at least 0.945?

Q 118

Thirty percent of a magazine's subscribers are female. A random sample of 50 subscribers is taken. Answer the following questions using Excel.
a.What is the probability that the proportion of females from this sample is at most 0.25?
b.What is the probability that the proportion of females from this sample is between 0.22 and 0.28?
c.What is the probability that the proportion of females from this sample is within .03 of the population proportion?

Q 119

The proportion of Americans who support the death penalty is 0.53. A sample of 1000 randomly selected Americans is surveyed by telephone interview. Use Excel to answer the following questions.
a.What is the probability that the sample proportion of those supporting the death penalty will be less than 0.50?
b.What is the probability that the sample proportion of those supporting the death penalty will be at least 0.55?
c.What is the probability that the sample proportion of those supporting the death penalty will be between 0.50 and 0.55?
d.For samples of size 1000, 15% of all sample proportions are at most what value?