Question

suppose the population average amount of dog biscuits in a bag is 40 pounds with a standard deviation of 6 pounds. a simple random sample of 64 bags is selected. what is the probability the sample mean weight will be within 1.5 pounds of the population mean?

Answer 1

Solution :

Given that,

mean = = 40

standard deviation = = 6

= / n = 6 / 64 = 0.75

= P[(-1.5) / 0.75< ( - ) / < (1.5) / 0.75)]

= P(-2 < Z < 2)

= P(Z < 2) - P(Z < -2)

= 0.9772 - 0.0228

= 0.9544

Probability = 0.9544