Suppose that the probability density function ofthe length of computer cables is f (x) = 0.1 from 1200 to1210 millimeters. a. Determine the mean and standard deviation of the cablelength. b. If the length specifications are 1195 < x < 1205 millimeters, what proportion of cables is within specifications?

Notice that for implies that elsewhere, since

where is a random variable representing cable lengths according to the PDF .

a. By definition of expectation, the mean is

The variance is

where

so that the variance is , making the standard deviation .

b. The proportion of cables within specs is

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:

details

step-by-step explanation: