In: Statistics and Probability
Solution :
Given that,
mean =
= 123
standard deviation =
= 21
n=15
=
=123
=
/
n = 21/
15 = 5.42
P( > 126) = 1 - P(
<126 )
= 1 - P[(
-
) /
< (126-123) /5.42 ]
= 1 - P(z <0.55 )
Using z table
= 1 - 0.7088
probability= 0.2912