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Title: Find X_bar, diner question Post by: durocksrock on Feb 14, 2022 The number of diners at a restaurant each day is recorded and a daily average is calculated every month (assume 30 days in a month). The number of diners each day has a mean of 121 and a standard deviation of 51, but does not necessarily follow a normal distribution.
The probability that a daily average over a given month is greater than x_bar is 2.5%. Calculate x_bar. Give your answer to 3 decimal places. Title: Re: Find X_bar, diner question Post by: bio_man on Feb 14, 2022 See if this helps:
X ~ N ( µ = 121 , σ = 57 ) P ( X > ? ) = 1 - P ( X < ? ) = 1 - 0.025 = 0.975 Looking for the probability 0.975 in standard normal table to calculate critical value Z = 1.96 Z = ( X - µ ) / σ 1.96 = ( X - 121 ) / 57 X = 232.720 P ( X > 232.720 ) = 0.025 |