The monthly expenditures on food by single adults living in one neighborhood of los angeles are normally distributed with a mean of $410 and a standard deviation of $75. determine the percentage of samples of size 9 that have mean expenditures within $20 of the population mean expenditure of $410.

0.5763

Step-by-step explanation:

We need to estimate the standard error of the mean.

Standard error of the mean = standard deviation of the original distribution/√sample size

Standard error of the mean = 75/√9 = 25

Now we can use this Standard error to estimate z as follows:

Z = (x – mean)/standard deviation

We want the mean expenditures within $20, so x – mean = 20 and -20

Z = (20)/25

Z = 0.8

Z = (-20)/25

Z = -0.8

Using  a Z table we can find probability  

P (-0.8<z<0.8)= 0.5763

6.9

step-by-step explanation:

simple math really

6 1/2 times 0.6 = 3.9

but if you are just doing 6 and not 6 1/2 then the answer is 3.6

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)