The mean of the data is 18.25 find the variance

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Awoman who is 64 inches with a shoulder width of 16 inches. write an equation relating the height h to the width w. find the height of a woman who has ashoulder width of 18.5 inches

Harry owes the bank money. to repay his debt, he paid $150 back to the bank each month. after 10 months, his remaining debt was $6900. what was the original amount of harry's debt? how long did it take harry to pay back his entire debt?