If Z-x.fu ,cxpress x Z Zg in its simplest form-

Five automobiles of the same type are to be driven on a 300-mile trip. The first two will use an economy brand of gasoline, and the other three will use a name brand. Let X1, X2, X3, X4, and X; be the observed fuel efficiencies (mpg) for the five cars. Suppose these variables are independently distributed with 1 – 112 - 20, l3 - 4 - Hs – 24, and of – o3 – 4 for the economy brand and o = o% = o = 3.5 for the name brand. Define the rv Y by X1+ X2 X3 + X4+ X, Y = 2 3 so that Y is a measure of the difference in efficiency between economy gas and name-brand gas. Compute oy [3 decimal places]

At inventory time, 435 pounds of magnet wire for winding motors is available. In ten successive days, 15 pounds, 6 pounds, 24 pounds, 12 pounds, 3 pounds, 8 pounds, 17 pounds, 32 pounds, 16 pounds, and 13 pounds of wire are taken out of stock. How many pounds are left?

You go to the doctor and he gives you 16 milligrams of radioactive dye. After 24 minutes, 5.75 milligrams of dye remain in your system. To leave the doctor's office, you must pass through a radiation detector without sounding the alarm. If the detector will sound the alarm if more than 2 milligrams of the dye are in your system, how long will your visit to the doctor take, assuming you were given the dye as soon as you arrived? Give your answer to the nearest minute. You will spend______ minutes at the doctor's office.