Full question:
Every 5 years the Conference Board of the Mathematical Sciences surveys college math departments. In 2000 the board reported that 51% of all undergraduates taking Calculus I were in classes that used graphing calculators and 31% were in classes that used computer assignments. Suppose that 16% used both calculators and computers. a) What percent used neither kind of technology? b) What percent used calculators but not computers? c) What percent of the calculator users had computer assignments? d) Based on this survey, do calculator and computer use appear to be independent events? Explain.
Answer:
a. 34%
b. 35%
c. 31.4%
d. Independent events
Explanation:
a. To calculate percentage that used neither kind of technology, we already know those that use the technologies and total taking calculus so:
100%-51%-31%-16%= 34%
b. Percentage that used calculators but not computers.
= 51%-16%=35%
c. Percentage of the calculator users that had computer assignments?
= 16/51×100=31.4% (there are 16 people using both so that as a percentage of 51 people using calculators)
d. Independent events are events that do not affect the other, such that occurrence of one does not define occurrence of the other. Since percentage of calculator and computer assignment users is close to those who are not using any, we can say they are independent events.
