## Statistics

20 Feb

1. The length of time that it takes students to complete their statistics exam is what type of data?

Select one:
a. Categorical Data
b. Continuous Data
c. Qualitative Data
d. Discrete Data
2. A survey was conducted to determine the preferred news source for homeowners in Illinois (Television, Internet or Newspaper). 10,000 households were divided by income level and households from each income level were randomly selected to participate in the survey. What sampling technique is being used?
Select one:
a. Systematic
b. Random
c. Stratified
d. Cluster
3. The weekly salaries (in dollars) of a sample of 10 medical assistants are listed below:
\$805   \$747    \$546   \$450   \$1109    \$975    \$809   \$767    \$450   \$690

What is the mean salary of the registered nurses?

Select one:
a. \$800
b. \$740
c. \$810
d. \$735
4. The weekly salaries (in dollars) of a sample of 10 medical assistants are listed below:
\$805   \$747    \$546   \$450   \$1109    \$975    \$809   \$767    \$450   \$690

What is the median salary of the registered nurses?

Select one:
a. \$767
b. \$747
c. \$690
d. \$757
5. The weekly salaries (in dollars) of a sample of 10 medical assistants are listed below:
\$805   \$747    \$546   \$450   \$1109    \$975    \$809   \$767    \$450   \$690

What is the standard deviation of the nurses’ salaries?

Select one:
a. \$329.50
b. \$213.20
c. \$659
d. \$14.60
6. Seven customers enter a clothing store and are observed to determine if they will make a purchase. The store owner states that there is a 75% chance of a customer making a purchase. The random variable x represents the number of customers making a purchase.
What is the probability that exactly 4 customers make a purchase?
Select one:
a. 0.25
b. 0.75
c. 0.57
d. 0.17
7. Seven customers enter a clothing store and are observed to determine if they will make a

purchase. The store owner states that there is a 75% chance of a customer making a purchase.

The random variable x represents the number of customers making a purchase. What is the

probability that exactly 5 customers make a purchase?

Select one:
a. 0.31
b. 0.71
c. 0.76
d. 0.52
8. Seven customers enter a clothing store and are observed to determine if they will make a purchase. The store owner states that there is a 75% chance of a customer making a purchase.  The random variable x represents a customer making a purchase.
Calculate the mean, variance and standard deviation for the number of customers that make a purchase.
Select one:
a. Mean = 5.25, Variance = 1.31 , Standard Deviation = 1.15
b. Mean = 1.75, Variance =1.31 , Standard Deviation = 2.62
c. Mean = 5.25 , Variance = 1.31 , Standard Deviation = 2.62
d. Mean = 1.75, Variance = 5.25 , Standard Deviation = 2.29
9. The length of time that it takes students to complete the entrance exam for a University is normally distributed with a population mean of µ = 120 minutes and σ = 30 minutes.
What is the probability that 1 randomly selected student will take longer than 165 minutes to complete the entrance exam?
Select one:
a. 0.9032
b. 0.9332
c. 0.0668
d. 0.0968
10. The length of time that it takes students to complete the entrance exam for a University is normally distributed with a population mean of µ = 120 minutes and σ = 30 minutes.
What is the probability that the average of 25 randomly selected students will take between 115 and 125 minutes?
Select one:
a. 0.8333
b. 0.4066
c. 0.5934
d. 0.2033