Electricity consumption by the residents in a local community is normally distributed, with a mean of 32 kilowatt-hours per day. Ninety-five percent of the residents use between 28 and 36 kilowatt-hours per day. What is the standard deviation of electricty consumption in the population?

The standard deviation is 2

Step-by-step explanation:

Electricity consumption by the residents in a local community is normally distributed, with a mean of 32 kilowatt-hours per day.

We have that, 95% of the residents use between 28 and 36 kilowatt-hours per day.

According to the empirical rule , 95% of the distribution falls within two standard deviations of the mean.

We can use the upper x=36, and the mean,

to find the standard deviation using the formula:

We substitute to get:

Therefore the standard deviation is 2.

step-by-step explanation:

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?