Question

The delivery times for all food orders at a fast-food restaurant during the lunch hour are normally distributed with a mean of 14.7 minutes and a standard deviation of 3.7 minutes. Let R be the mean delivery time for a random sample of 40 orders at this restaurant. Calculate the mean and standard deviation ofX Round your answers to two decimal places. Mean of RD T' minutes Standard deviation of 2 minutes

Answer 1

estimated sample mean X is 14.7 minutes

sample standard deviation is ≈ 0.59 minutes.

Explanation:

Let X be the mean delivery time for a random sample of 40 orders at this restaurant, then

X can be estimated as 14.7 minutes (mean delivery time for all food orders at a fast-food restaurant during the lunch hour)

Let s be the standard deviation of delivery time for a random sample of 40 orders at this restaurant, then

`s=(3.7)/(√(40) )` ≈ 0.59 where

• 3.7 is the standard deviation of the delivery times for all food orders at a fast-food restaurant during the lunch hour
• 40 is the sample size