Arandom sample of 50 cars in the drive-thru of a popular fast food restaurant revealed an average bill of $18.21 per car. the population standard deviation is $5.92. round your answers to two decimal places.

(a) state the point estimate for the population mean cost of fast food bills at this restaurant $

(b) calculate the 95% margin of error. $

(c) state the 95% confidence interval for the population mean cost of fast food bills at this restaurant. $ ≤ µ ≤ $

(d) what sample size is needed if the error must not exceed $1.00? n =

a)

b) 1.64

c) (16.57,19.85)

d) The sample size must be 135 or greater if the error must not exceed $1.00.

Step-by-step explanation:

We are given the following information in the question:

Sample size, n = 50

Sample mean =   $18.21

population standard deviation = $5.92

a)  Point estimate for the population mean cost

b) Margin of error =

Margin of error =  

c) 95% Confidence interval

Putting the values, we get,

d) Marginal error less than $1.00

Thus, the sample size must be 135 or greater if the error must not exceed $1.00.

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step-by-step explanation: