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. The data is shown in the table below.
Number of Conferences
Days Lasted
4
2
36
3
18
4
19
5
4
6
1
7
1
8
1
9
Calculate the sample mean of days of engineering conferences.
