Question

Q2.​The mean and standard deviation of distributions of 100 and 150 items are 50, 5 and 40, 6, respectively. Find the mean and standard deviation of all the 250 items taken together.

Answer 1

Answer: mean of all 25 items  = 44

standard deviation of all 250 items  = 5.6

Step-by-step explanation:

i.) = 100

ii.)  = 150

iii) mean =

iv) standard deviation =