Question

Given a normal distribution with muequals50 and sigmaequals4​, and given you select a sample of n equals 100​. What is the probability that Upper X overbar is above 50.1​?

Answer 1

Solution :

Given that,

mean = = 50

standard deviation = = 4

n = 100

= 50

₌ / n = 4 100 = 0.4

P ( > 50.1 )

= 1 - P ( < 50.1 )

= 1 - P ( - /) < (50.1 - 50 /0.4)

= 1 - P( z < 0.1 / 0.4 )

= 1 - P ( z < 0.25 )   

Using z table

= 1 - 0.5987

= 0.4013

Probability = 0.4013