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

estimated sample mean X is 14.7 minutes

sample standard deviation is ≈ 0.59 minutes.

Step-by-step 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

≈ 0.59 where

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)