What is X? the sample mean?Let X1,X2 .... X16 be a random sample from a normal distribution N(77,25).
Compute a)P(77<X<79.5)
b) P(74.2<X<78.4)
RonL
The sample mean of a sample of size from a normal distributionLet X1,X2 .... X16 be a random sample from a normal distribution N(77,25).
Compute a)P(77<X<79.5)
b) P(74.2<X<78.4)
has a normal distribution; .
So in this case the SD of the sample mean is so:
,
Which may be looked up in a suitable table:
.
The second question is:
Which from tables I make
RonL