ELABORATIONS BASED ON FINAL EXAM!!
1.An online retailer selling workout apparel has a large increase in sales during
December and declares that their weekly newspaper ad resulted in higher sales.
What misuse of statistics may the retailer have used in making this decision?:
Association and Causation
2.An educator collects eighth grade math scores from a local school and used this
data to recommend curriculum changes for grades 8 - 12. What misuse of statistics
may the educator have used in making this recommendation?: Not a representative
sample
3.An economist wishes to study the distribution of household income in a
Midwestern city. He randomly selects a sample from 12 households. He
notices two large incomes in his sample. Which measure best represents the middle of
the incomes?: Median
4.A cable company offers its customers both cable television and internet. What
statistical rule should be used to determine the probability that cus- tomers will
have both cable television and internet?: Multiplication
5.A department store is considering a new credit policy to reduce defaults on
payments. Its records show that 95% of defaults have at least 2 late payments. Also,
3% of all customers default and 30% of those customers who have not defaulted have
a least 2 late payments. What statistical rule should be used to find the probability
that a customer will default given that at least 2 payments were late?: Bayes Theorem
6.Based on quality checks at a plastic bags manufacturer, the breaking strength of
their bags has a mean of 50.5 and a standard deviation of 1.6. A customer's test of the
bags finds bag strength of 54.2 or less. Which statistical measure should be used to
help determine the probability of the customer's test occurring?: z-score
7.The mean of 100 bank customers' waiting times for teller service is 5.8 minutes
with a standard deviation of 1.5. What time range would represent a 95.4%
probability customer waiting time?: 2.8 to 8.8
8.The revenue of NBA teams ranges from $226 million for the New York Knicks to
$92 million for the Milwaukee Bucks. Which statistic would measure how far each
and all NBA team's revenue is from the NBA revenue mean?: Variance
9.A local plumbing company is analyzing to see how the number of weeks taken for
their payment receipts is distributed. Which graphical analysis tech- nique should
they use?: Histogram
10.Given the following data set: 60, 41, 30, 15, 34, 30 What is the Median?: 32
11.A loan officer compares the interest rates for 48 month fixed-rate loans and 48
month variable-rate auto loans. Two independent, random samples of auto loans are
selected. Which two results happen when the null hypothesis
1/
3