A consumer advocacy group tested the "on-air" lifetimes of a random sample of 162 cell phone batteries. The mean lifetime was 2.9 hours with a standard deviation of 0.4 hours. The lifetimes are approximately bell-shaped. Estimate the number of batteries with lifetimes between 2.1 hours and 3.7 hours.
A)110
B)8
C)almost all (greater than 154)
D)154

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The Answer of A consumer advocacy group tested the "on-air" lifetimes of a random sample of 162 cell phone batteries. The mean lifetime was 2.9 hours with a standard deviation of 0.4 hours. The lifetimes are approximately bell-shaped. Estimate the number of batteries with lifetimes between 2.1 hours and 3.7 hours.
A)110
B)8
C)almost all (greater than 154)
D)154

A Consumer Advocacy Group Tested the "On-Air" Lifetimes of a Random