The Roper Organization (1992) conducted a study as part of a larger survey to ascertain the number of U.S. adults who had experienced phenomena such as seeing a ghost, "feeling as if you left your body," and seeing a UFO. A representative sample of adults (18 and over) in the continental United States were interviewed in their homes during July, August, and September 1991. The results when respondents were asked about seeing a ghost are shown in the following table:
|
|
Reportedly Has Seen a Ghost
|
|
|
Yes
|
No
|
Total
|
|
Aged 18 to 29
|
212
|
1313
|
1525
|
|
Aged 30 or over
|
465
|
3912
|
4377
|
|
Total
|
677
|
5225
|
5902
|
a. In each age group, find the percentage who reported seeing a ghost.
b. What is the relative risk of reportedly seeing a ghost for adults under 30 compared to adults 30 and over? Write your answer in a sentence that could be understood by someone who knows nothing about statistics.
c. Repeat part (b) using increased risk instead of relative risk.
d. What are the odds of reportedly seeing a ghost to not seeing one in the older group?