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

step-by-step explanation:

i think something is missing in your question because y-1=(x-12) would not pass through the point (-4,-3). because if you replace x by -4 your are supposed to find y=-3 which is not the case her. if you replace x by -4 you find =-15.

i assume the right equation is y-1=1/4*(x-12) because this one is passing through both your points (if you are interested to know how i found that out i can tell you).

in this equation if i replace x by -4 i find y=-3 and if i replace x by 12, i find y=1 so the line representing this equation is passing through those 2 points.

then the standard form of the equation is finding an expression of y in function of x

y-1=1/4*(x-12)

y=x/4-3+1

y=x/4-2

hope that .

do you confirm there was a mistake in the question?

you need to give us more information since we can't answer