Data from the Bureau of Labor Statistics' Consumer ExpenditureSurvey show customers spend an average of (µ) $608 a year forcellular phone services. The standard deviation of annual cellularspending is (σ) $132. The random variable, yearly cellularspending, is denoted by X. We plan to select a random sample of 100cellular customers.
11.
The sampling distribution of X¯X¯
Select one:
a. is not normal because the sample size is too small
b. is normal due to the Chebyshev's Theorem
c. is normal due to the Central Limit Theorem
d. is not normal because the sample size is too large
12.
The standard error (SE) of X¯X¯ is
Select one:
a. 60.8
b. 1.32
c. 132
d. 13.2
13.
What is the probability that a random sample of 100 cellularcustomers will provide an average(X¯X¯) that is within $25 of thepopulation mean (µ)?
Select one:
a. 3%
b. 94%
c. 97%
d. 6%
14.
The probability in the PRECEDING question would------ if we were to increase the sample size (n) from 100 to151.
Select one:
a. be zero
b. stays the same
c. increase
d. decrease
15.
Suppose we reduce the sample size (n) from 100 to 25. Thesampling distribution of X¯X¯ will be normal only if
Select one:
a. X has a right skewed distribution
b. X is normally distributed
c. X has a bi-modal distribution
d. X has a left skewed distribution
