The table summarizes responses of 4383 subjects in a recent General Social Survey to the question, “Within the past month, how many people have you known personally that were victims of homicide?”
Number of People You Have Known
Who Were Victims of Homicide
Number of Victims Frequency
0............. 3944
1............. 279
2............. 97
3............. 40
4 or more............ 23
Total............. 4383
a. To find the mean, it is necessary to give a score to the “4 or more” category. Find it, using the score 4.5. (In practice, you might try a few different scores, such as 4, 4.5, 5, 6, to make sure the resulting mean is not highly sensitive to that choice.)
b. Find the median. The “4 or more” category is not problematic for it.
c. If 1744 observations shift from 0 to 4 or more, how do the mean and median change?
d. Why is the median the same for parts b and c, even though the data are so different?