Download assignment1 - United International College

Assignment 1
1. Below we list several variables. Which of these variables are quantitative and which are
qualitative? Explain.
a. The dollar amount on an accounts receivable invoice.
b. The net profit for a company in 2010.
c. The stock exchange on which a company’s stock is traded.
d. The national debt of the United States in 2010.
e. The advertising medium (radio, television, or print) used to promote a product.
2. Classify each of the following qualitative variables as ordinal or nominative. Explain your
answers.
Qualitative Variables
The Corresponding Categories
Motion picture classifications
G
PG
PG-13
R
NC-17
X
Level of education
Elementary Middle school High school
College Graduate school
Rankings of the top 10 college
Football teams
1
Exchange on which a stock is traded
AMEX NYSE NASDAQ Other
2
3 4 5 6 7 8 9 10
3. Download the dataset TrashBag from ISPace.
a. Use SPSS to generate a stem-and-leaf display of the sample of 40 breaking strengths in the
trash bag case. And describe the distribution of breaking strengths.
b. Write out the 3 smallest breaking strengths as they would be expressed in the original data.
c. Do there appear to be any breaking strengths that are outliers?
d. Use SPSS to get a histogram of the sample of 40 breaking strengths.
e. What are the advantages of using a stem-and leaf display?
f. If a data set consists of 1,000 measurements, would you summarize the data set by using a
stem-and-leaf display or a histogram? Explain.
4. Calculate the mean, median and mode, range, variance, standard deviation of the following
population of numbers:
9, 8, 10, 10, 12, 6, 11, 10, 12, 8
5. Use SPSS to calculate the mean, median and mode, range, variance, standard deviation of the
following sample of numbers, and paste the SPSS output to your answer sheet.
110, 120, 70, 90, 90, 100, 80, 130, 140
6. The BANK CUSTOMER WAITING TIME CASE (Download the dataset WaitTime from
ISPace)
WaitTime file presents the waiting times for teller service during peak business hours of 100
randomly selected bank customers.
a. Does the sample mean provide evidence that the mean of the population of all possible
customer waiting times during peak business hours is less than six minutes (as is desired by
the bank manager)? Explain your answer. (Use SPSS to get the sample mean)
b. Use the stem-and-leaf display to verify that the median of the waiting times is 5.25. How do
the mean and median compare? What does the stem-and-leaf display tell you about why they
compare this way? (Use SPSS to construct the stem-and-leaf display)