Download business statistics – spss examples

BUSINESS STATISTICS – SPSS EXAMPLES
1. A manufacturing company produces electric insulators. If the insulator breaks when in use,
you are likely to have a short circuit. To test the strength of insulators, we carry out destructive
testing to determine how much “Force” is required to break the insulator. We measure the
force by observing how many pounds are applied to the insulator before it breaks. File
FORCE.sav lists thirty values from this experiment. Construct 95% confidence interval estimate
for the population mean force required to break the insulator.
2. The data in the file INVOICES.sav indicates the amounts (in dollars) in a random sample of 12
invoices. Over the past five years, the mean amount per sales is $120. As an accountant for the
company, you need to inform the finance department if this amount has changed.
3. Comparing sales from End-Aisle displays and Normal displays – Does the type of display
used in a supermarket affect the sales of products? As the regional manager of ABC Foods, you
are interested in comparing the sales volume of ABC cola when you display the soft drink in the
normal shelf location as compared to an end-aisle promotional display. To test the
effectiveness of the end-aisle displays, you select 20 stores from the ABC supermarket chain
that all experience similar storewide sales volumes. You then randomly assign 10 of the 20
stores to group 1 and 10 to group 2. The manager of the 10 stores in group 1 place the ABC cola
in the regular shelf location alongside the other cola products. The 10 stores in group 2 use the
special end-aisle promotional display. At the end of one week, the sales of ABC cola are
recorded. The data are given in file COLA.sav. How can you determine whether sales of ABC
cola using the end-aisle displays are the same as those when the cola is placed in the regular
shelf location? How can you decide if the variability in ABC cola sales from store to store is the
same for the two types of displays? How could you use the answers to these questions to
improve sales of ABC colas?
4. A software applications company is developing a new financial applications package.
Because the computer processing time is an important decision criterion, the developer wants
the new package to have the same features and capabilities as the current market leader while
providing results faster than the current leading package. A sample of 10 financial applications
projects were considered and for each of these projects, the processing times using new
software package and the current package were recorded, as in file COMPTIME.sav. Is the new
software package faster?
5. You are the production manager of the Perfect Parachute Company. Parachutes are woven in
your factory using a synthetic fiber purchased from one of the four suppliers. For obvious
reasons, one of the most important quality characteristics of a parachute is its strength. To help
answer this question, an experiment was conducted to determine if any significant differences
exist in the strength of parachutes woven from synthetic fibers from the different suppliers. The
results of this experiment (in terms of tensile strength required to tear the parachute) are
contained in the data file PARACHUTE.sav. Analyze the data.
6.
Consider the data relating to a sample of 121 mutual funds as in the file
MUTUALFUND2004.sav. You are required to prepare a statistical analysis to determine
whether there is any relationship between the Objective and the Fees.
7. The sales for Sunflowers, a chain of apparel stores for women, have increased during the past
12 years as the chain expanded the number of stores. Until now, Sunflowers senior managers
selected sites based on subjective factors such as availability of a good lease or the perception
that a location seemed ideal for an apparel store. As the new director of planning, you need to
develop a systematic approach to selecting new sites that will allow Sunflowers to make better
informed decisions for opening new stores. You believe that the size of the store significantly
contributes to the success of a store and you want to use this relationship in the decision
making process. The goal is to forecast annual sales for all new stores based on store size. To
examine the relationship between the store size (square footage) and its annual sales, a sample
of 14 stores was selected. The data is given in file SITE.sav. Use SPSS to calculate the correlation
and arrive at the linear regression equation for prediction.
8. You are the marketing manager of Omni Foods, a large food products company. Omni Foods
is preparing a nationwide introduction of a new product, a high-energy bar called OmniPower.
Sales of competitors’ high-energy bars have skyrocketed. Before introducing the bar
nationwide, you need to determine the effect of price and in-store promotion on the sales of
OmniPower. You plan to use a sample of 34 stores in a supermarket chain for a test-market
study of OmniPower sales. The results of test-market study are presented in file OMNI.sav. Fit a
multiple regression model.