Introduction to Statistics and Data Analysis
Chapter 11- Independent OR Dependent
For each of the situations presented below, determine of the samples are independent or dependent.
EXPLAIN your choice.
A. Which coating (A or B) produces higher strength? A sample of 5 CD’s is treated with coating A, while a
second sample of 5 CD’s is treated with coating B. Each CD is then tested for strength.
B. Does environment affect intelligence? Researchers identified 25 sets of identical twins in which one twin
was raised by biological parents and the other one was raised by adoptive parents. Each twin was given an IQ
C. Which drug (A or B) relieves severe headaches faster? A sample of 10 people who suffer from severe
headaches is given drug A for their pain one month and drug B another month. Time to headache is relief is
D. A total of 20 people enter a study to determine the benefits of a new drug designed to reduce cholesterol. The
new drug is given to 10 people, while a placebo is given to the other 10 people. After a period of three months,
the reduction in cholesterol is measured in each person.