Question

A sample of 12 measurements has a mean of 34 and a standard deviation of 4.5. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 34 each.

A. Find the mean of the sample of 14 measurements.

Mean =

B. Find the standard deviation of the sample of 14 measurements.

Answer 1

Mean will remain unchanged as 34. but if the new values are different new mean will be computed as

12(34)+2(34)
-------------
12+2

476/14
=34

sample standard deviation

=

Answer 2

Part B op

Answer 3

20.1656