Data from the Bureau of Labor Statistics’ Consumer Expenditure Survey show that annual expenditures for cellular phone services per consumer unit increased from $242 in 2001 to $619 in 2007. Let the standard deviation of annual cellular expenditure be $64 in 2001 and $204 in 2007. [You may find it useful to reference the z table.] a. What is the probability that the average annual expenditure of 109 cellular customers in 2001 exceeded $234? (Round "z" value to 2 decimal places, and final answer to 4 decimal places.)

b. What is the probability that the average annual expenditure of 109 cellular customers in 2007 exceeded $596? (Round "z" value to 2 decimal places, and final answer to 4 decimal places.)

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?

a

step-by-step explanation:

-9

step-by-step explanation:

step-by-step explanation: