A food truck sells an average of 1240 black bean lattes with a standard deviation of 80.What level of customer demand represents the 15th percentile for black bean lattes?
A)1066
B)1157
C)1183
D)1204

Question

Quizplus · Accepted Answer

To find the 15th percentile in a normally distributed set of data, we use the Z-score formula for a percentile, which is Z = (X - μ) / σ, where X is the value at the percentile, μ is the mean, and σ is the standard deviation. The Z-score corresponding to the 15th percentile is approximately -1.04. Plugging in the values we have: -1.04 = (X - 1240) / 80. Solving for X gives us X ≈ 1240 + (-1.04)(80) ≈ 1240 - 83.2 ≈ 1156.8, which rounds to or is closest to the option B, 1157.

A Food Truck Sells an Average of 1240 Black Bean