Database Reference
In-Depth Information
Figure 3.27
Density plot of purchase size
8. How many sections does a box-and-whisker divide the data into? What are
these sections?
9. What attributes are correlated according to
Figure 3.18
? How would you
describe their relationships?
10. What function can be used to fit a nonlinear line to the data?
11. If a graph of data is skewed and all the data is positive, what mathematical
technique may be used to help detect structures that might otherwise be
overlooked?
12. What is a type I error? What is a type II error? Is one always more serious
than the other? Why?
13. Suppose everyone who visits a retail website gets one promotional offer or
no promotion at all. We want to see if making a promotional offer makes a
difference. What statistical method would you recommend for this
analysis?
14. You are analyzing two normally distributed populations, and your null
hypothesis is that the mean of the first population is equal to the mean
of the second. Assume the significance level is set at 0.05. If the
observed
p
-value is 4.33e-05, what will be your decision regarding the null
hypothesis?
