Statistics Quiz – Need it Done Today

Quiz attached.

92.183 Introduction to Statistics

Name:_____________________________________

Exam 1

September 21,2012

Be sure to show all your work.

Readability and Neatness are Important!!!

1. When Lance Armstrong won a record seventh Tour de France, there was a lot of interest in the rac

e.

The following is a list of variables based on data given on the history of the race.

Determine if the following items are categorical or numeric variables. In addition, if they are numeric, whether

they are discrete or continuous.

Variable Name	Data Type	Discrete or Continuous
a.	Year of Victory
b.	Winner
c.	Winning Rider’s Country
d.	Total time (Hr/Min/Sec)
e.	Average Speed (km/hr)
f.	Number of Stages
g.	Total Distance Ridden (km)
h.	Number of Starting Riders
i.	Number of Finishing Riders
j.	Rider’s Sponsor

2. The following data give the grade point averages of the Junior Class of Economics majors at a State University

3.2 2.5 2.1 3.7 2.8 2.0 1.9 3.8 2.4 3.9 2.8 2.5 3.3 3.1 2.8

a. Construct an ordered stem-and leaf plot of the GPA data.

b. Find the mean GPA for the Junior Economics majors, the median and the mode for their GPAs

c. Find the range, Q1 and Q3. What is the IQR for the GPAs.

d. Determine the Five Number Summary representing the GPA data.

e. What is the shape of the distribution of data on the GPAs (symmetric,

skewed to the left, skewed to the right)?

3. The Environmental Protection Agency (EPA) fuel economy estimates for automobiles tested recently predicted

a mean of 24.8 mpg with a standard deviation of 6.2 mpg for highway driving. Assume that the data is normally distributed. Using the

68-95-99.7 Rule,
Determine:

a. Within what interval you would expect the middle 68% of the autos gas mileages to be found?

b. What percent of the autos should get more than 31 mpg?

c. What percent of the autos should get between 31 and 37.2 mpg?

d. What percent of the autos would you expect to get less than 18.6 mpg?

e. What percent of the autos would have a gas mileage of no more than 12.4 mpg

f. What is the gas mileage of the worst 2.5% of the autos?

4. According to a survey by Kaiser Family Foundation, employers paid an average of $7954 per employee in

annual premiums to provide family health care for their employees, and each worker paid an average of $2080 toward these premiums. Assume that the current annual premiums paid by all workers for family health coverage are normally distributed with a mean of $2080 and a standard deviation of $300.

a. What is the probability that a worker pays less than $1730 per year for the family health coverage premium?

b. What percentage of the workers is paying between $1800 and $2400 per year toward the family health coverage premium?

c. What is the probability that a worker pays more than $2500 towards the family health coverage premium?

d. What percentage of the workers paid less than $2080 for their family health coverage premium?

e. What percentage of the workers paid more than $2080 for their family health coverage premium?