Astudy indicates that 18- to 24- year olds spend a mean of 140 minutes watching video on their smartphones per month. assume that the amount of time watching video on a smartphone per month is normally distributed and that the standard deviation is 15 minutes. complete parts (a) through (d) below. a. what is the probability that an 18- to 24-year-old spends less than 120 minutes watching video on his or her smartphone per month? the probability that an 18- to 24-year-old spends less than 120 minutes watching video on his or her smartphone per month is nothing. (round to four decimal places as needed.)

Answers:

a) 0.091

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 140 minutes

Standard Deviation, σ = 15 minutes

We are given that the distribution of time watching videos is a bell shaped distribution that is a normal distribution.

Formula:

a) P(time is less than 120 minutes)

Calculating the value from the standard normal table we have,

The probability that an 18- to 24-year-old spends less than 120 minutes watching video on his or her smartphone per month is 0.091

answer: the first one

step-by-step explanation: use a calculator and divide the minutes by the dollars.