A small flower shop takes orders by phone and then one of the staff florists is assigned to prepare the arrangement. The time it takes to process phone orders is normally
Distributed with a mean of 6 minutes and a standard deviation of 2.5 minutes. The time it
Takes for an arrangement to be completed is normally distributed with a mean of 35
Minutes and a standard deviation of 8.6 minutes. What is the probability that it will take
More than 50 minutes to process a phone order and complete the floral arrangement at
This flower shop?
A) 0.8413
B) 0.3413
C) 0.2167
D) 0.1587
E) 0.6843

Question

Quizplus · Accepted Answer

The total time is the sum of two normally distributed times: phone order (mean = 6, SD = 2.5) and arrangement (mean = 35, SD = 8.6). The combined mean is 41 minutes, and the combined standard deviation is √(2.5² + 8.6²) ≈ 8.9 minutes. To find the probability of taking more than 50 minutes, calculate the z-score: (50 - 41) / 8.9 ≈ 1.01. The probability of a z-score greater than 1.01 is approximately 0.1587.

A Small Flower Shop Takes Orders by Phone and Then