Question

a normally distributed population has mean 57.7 and standard deviation 12.1 .(a) find the probability that single randomly selected element X OF THE POPULATION IS LESS THAN 45 (b) find the mean and standard deviation of x for samples size 16. (c) find the probability that the mean of a sample of size 16 drawn from this population is less than 45

Answer 1

Solution :

Given that ,

mean = = 57.7

standard deviation = = 12.1

n = 16

= 57.7

= / n = 12.1 / 16 = 3.024

P( < 45) = P(( - ) / < (45 - 57.7) / 3.025)

= P(z < -4.20)

= 0