Know how to calculate sample size: A restaurant would like to estimate the average $ amount of a take-out order. The standard deviation is $15. If a 99% confidence level and an interval (error) of $5 is desired, how many customers should be in the sample? Which of the following examples would use the z-distribution:.
a. x = 100; µ = 99; s = 5; n = 70
b. x = 50; µ = 53; σ = 7; n = 15
c. x = 7; µ = 4; s = 1; n = 20
d. x = 15; µ = 17; σ = 3; n = 45

Will give the box plots below show the math scores of students in two different classes: class a 55 72 75 89 95 class b 55 70 75 94 100 based on the box plots, which statement is correct? a: the median score of class a is greater than the median score of class b. b: the lower quartile of class a is greater than the lower quartile of class b. c: the upper quartile of class a is greater than the upper quartile of class b. d: the maximum score of class a is greater than the maximum score of class b.