Question

The population mean and standard deviation are given below. Find the indicated probability and determine whether a sample mean in the given range below would be considered unusual. If convenient, use technology to find the probability. For a sample of n=3636, find the probability of a sample mean being less than 12, 752 or greater than 12,755 when μ =12,752 and σ =1.5

Answer 1

Solution :

Given that,

mean = = 12752

standard deviation = = 1.5

n = 3636

= 12752

= / n = 1.5 / 3636 = 0.0249

P( <12752 ) = P(( - ) / < (12752-12752 ) /0.0249 )

P( < 12752) = P(Z < 0)

P( < 12752) = 0.5 Using z table,

Probability = 0.5