Suppose the lengths of phone calls to the receptionist of a small company are i. i.d. with a mean of 5 minutes and an SD of 8 minutes.
Let 1,2,…, be the lengths of calls in minutes, and let
= 1/ [lim(=1→)] ∑ ,
be the sample average length. In each of the following parts, either find the chance exactly, or approximate it, or bound it. Do the best you can with the information given.
a) P(|₁₆ − 5|<4)
b) P(|₁₆₀₀ − 5|<0.4)

d

step-by-step explanation:

d

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations:

i think it is 70

step-by-step explanation: