Sample Statistics Exam #500

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

1.  Which is the following is correct? 

a.  The probability of a type I error is 

β

. 

b.  The probability of a type II error is (1 - 

β

). 

c.  The probability of a type II error is 

α.

d.  The probability of a type I error is (1 - 

α

). 

e.  none of the above 

2.  A random sample of 10 items is taken from a normal population.  The sample had a mean of 82 and a 

standard deviation is 26.  Which is the appropriate 99% confidence interval for the population mean? 
a. 

b. 

c. 

d. 

e.  none of the above 

3.  A manufacturer of contact lenses is studying  the curvature of the lenses it sells.  In particular, the last 500 

lenses sold had an average curvature of 0.5.  The population is  
a.  the 500 lenses. 
b. 0.5. 
c.  the lenses sold today. 
d.  all the lenses sold by the manufacturer. 
e.  none of the above 

4.  According to the empirical rule, the bell or mound shaped distribution will have approximately 68% of the 

data within what number of standard deviations of the mean? 
a. one 

standard 

deviation 

b.  two standard deviations 
c.  three standard deviations 
d. four 

standard 

deviations 

e.  none of the above 

5.  A random sample of 5 mosquitos is sampled. The number of mosquitos carrying the West Nile Virus in the 

sample is an example of which random variable? 
a. normal 
b. student’s 

t 

c. binomial 

d. uniform 
e.  none of the above 

6.  A political scientist is studying voters in California.  It is appropriate for him to use a mean to describe