A Manufacturer of NFL Regulation Footballs Uses a Machine to Inflate

question 102

Multiple Choice

A manufacturer of NFL regulation footballs uses a machine to inflate its new balls to a pressure of 13.5 pounds (σ = .1) . When the machine is properly calibrated, the mean inflation pressure is 13.5 pounds, but uncontrollable factors can cause the pressure of individual footballs to vary. For quality control purposes, the manufacturer wishes to estimate the mean inflation pressure to within .025 pounds of its true value with 99 percent confidence. What sample size should be used?

• A) 677
• B) 107
• C) 35
• D) 27
• E) 11

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Definitions:

Stirrup

A light frame or ring that holds the foot of a rider, attached to the saddle in horseback riding.

Cochlea

A spiral-shaped cavity of the inner ear that plays a key role in the sense of hearing.

Retina

The light-sensitive layer of tissue at the back of the inner eye, which converts light images into electrical signals sent to the brain.

Pinna

The visible part of the ear that is outside the head, responsible for collecting sound waves and directing them into the ear canal.