Question

In: Statistics and Probability

A random sample of nequals100 observations is selected from a population with muequals31 and sigma equals...

A random sample of nequals100 observations is selected from a population with muequals31 and sigma equals 24. Complete parts a through f.

Find

​P(x overbarxgreater than or equals≥​28).

Solutions

Expert Solution

Solution :

mean = = 31

standard deviation = = 24

n = 100

= = 31

= / n = 24 / 100 = 2.4

P( 28) = 1 - P( 28)

= 1 - P[( - ) / (28 - 31) /2.4 ]

= 1 - P(z -1.25)

Using z table,    

= 1 - 0.1056

= 0.8944


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