Question
In: Statistics and Probability
A random sample of size 36 is taken from a population having mean 20 and variance...
A random sample of size 36 is taken from a population having mean 20 and variance 9.What is the probability that the sample meanXwill be at least 21?
Solutions
Expert Solution
Solution :
Given that,
mean = 
= 20
variance=9
standard deviation = 
= 
9=3
n=36
=
=20
=
/
n = 3 / 36 = 0.5
P( > 21) = 1 - P(
<21 )
= 1 - P[(
-
) /
< (21-20) /0.5 ]
= 1 - P(z <2 )
Using z table
= 1 - 0.9772
= 0.0228
probability= 0.0228
orchestra answered 3 years agoRelated Solutions
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