In a recent issue of the IEEE Spectrum, 84 engineering conferences were announced. Four conferences lasted two days. Thirty-six lasted three days. Eighteen lasted four days. Nineteen lasted five days. Four lasted six days. One lasted seven days. One lasted eight days. One lasted nine days. Let X = the length (in days) of an engineering conference.

a. Organize the data in a chart. (Round your answers to four decimal places.)

X	Frequency	relative frequency	cumulative relative frequency
2
3
4
5
6
7
8
9

b. Find the median:

Find the first quartile:

Find the third quartile:

c. Find the 65th percentile.

d. Find the 20th percentile. e. Construct a box plot of the data. f. The middle 50% of the conferences last from--- days to---

g. Calculate the sample mean of days of engineering conferences. (Round your answer to two decimal places.)

h. Calculate the sample standard deviation of days of engineering conferences. (Round your answer to two decimal places.) i. Find the mode. j. If you were planning an engineering conference, which would you choose as the length of the conference: mean, median, or mode? Explain why you made that choice.

k. Give two reasons why you think that three to five days seem to be popular lengths of engineering conferences. (Select all that apply.)