Answer: 2943
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Step-by-step explanation:
S = sum of the salaries of the first 15 employees
S/15 = mean of the 15 salaries
S/15 = 2930
S = 15*2930
S = 43950
The 15 workers salaries add to 43950.
If we add on a new 16th salary of 3138, then the sum bumps up to
S+3138 = 43950+3138 = 47088
This is the sum of the 16 workers salaries. Divide this over 16 to get the new average
47088/16 = 2943
The new mean is 2943
It is larger than the old mean because the 16th salary is larger than the mean. Effectively this new salary pulls on the mean to make it larger. With very distant outliers, the mean is pulled a lot which often causes problems. So this is why the median is a better measure of center in those situations. Either that measure of center, or using a trimmed mean works as well.