The mean of 100 values is 45. If 15 is added to each of the first forty

• Quant Statistics

The mean of 100 values is 45. If 15 is added to each of the first forty values and 5 is subtracted from each of the remaining sixty values, the new mean becomes

1. 45
2. 48
3. 51
4. 55

Solution

Original sum = 100 * 45

Change in sum = (40*15) - (60*5) = 600 - 300 = 300

Change in mean = 300/100 = 3

New mean = 45 + 3 = 48

The correct option is B.