The amount of jen's monthly phone bill is normally distributed with a mean of $76 and a standard deviation of $9. what percent of her phone bills are between $49 and $103

To solve this problem, we make use of the z statistic. The formula for z score is:

z = (x – u) / s

where x is sample value, u is the mean and s is the standard deviation

z (x = 49) = (49 – 76) / 9 = -3

Using the standard tables, P (z = -3) = 0.0013

z (x = 103) = (103 – 76) / 9 = 3

Using the standard tables, P (z = 3) = 0.9987

Hence,

P (-3 <= z <=3) = 0.9987 – 0.0013 = 0.9974

Therefore 99.74%

step-by-step explanation:

let

we know that

the y-intercept is the y-coordinate of the point when the value of x is equal to zero

so

the y-coordinate of the point a is the y-intercept

the answer part a) is

the value of y-intercept is

part b) find the slope m

we know that

the value of the slope is equal to

substitute the values

therefore

the answer part b) is

the value of the slope is equal to

the general answer is

the slope is

the value of y-intercept is

the answer is b. 60. each interior angle in 120, so the exterior angle must be 60 in order to add up to 180

step-by-step explanation: