Question

Out of 400 observations, 100 observations have the value one and the rest of the observations are zero. Find the mean and standard deviation of 400 observations together?​

Answer 1

Answer:

Answer

i=1

∑

97

x

i

=400−(3+4+5)

=388

i=1

∑

97

x

i

2

=2475−(9+16+25)

=2425

Variance =

N

∑

i

x

i

2

−(

N

∑x

i

)

2

=

47

2425

−(

97

388

)

2

=25−4

2

=25−16=9.