Multiple Choice
US smartphone owners aged 18 to 24 send an average of 2,022 text messages per month (Source: Businessinsider.com, 2013) .Suppose that the random variable "monthly text messages sent" is normally distributed.If exactly 20 percent of smartphone owners aged 18 to 24 send 3000 or more texts per month, what is the standard deviation of the random variable "monthly test messages sent"?
A) 404
B) 978
C) 1,164
D) 1,881
E) 2,196
Correct Answer:
Verified
Correct Answer:
Verified
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