Quality control is an important issue at ACME Company which manufacturers light bulbs. In order to conduct testing of the life hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted.
378, 361, 350, 375, 200, 391, 375, 368, 321

-What are the inner fences?
A)312.5,412.5
B)212.5,499.5
C)397.0,438.0
D)458.5,499.5
E)61.5,123.0

Question

Quality control is an important issue at ACME Company which manufacturers light bulbs. In order to conduct testing of the life hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted.
378, 361, 350, 375, 200, 391, 375, 368, 321

-What are the inner fences?
A)312.5,412.5
B)212.5,499.5
C)397.0,438.0
D)458.5,499.5
E)61.5,123.0

Quizplus · Accepted Answer

To find the inner fences, first, calculate the quartiles (Q1 and Q3) and then use the formula for inner fences: [Q1 - 1.5(IQR), Q3 + 1.5(IQR)], where IQR = Q3 - Q1. For the given data, after sorting: 200, 321, 350, 361, 368, 375, 375, 378, 391, Q1 = 350, Q3 = 375. IQR = 375 - 350 = 25. Inner fences = [350 - 1.5(25), 375 + 1.5(25)] = [312.5, 412.5].

Quality Control Is an Important Issue at ACME Company Which