The time between consecutive eruptions of Mont Etna in Sicily is exponentially distributed denoted by random variable X, with the mean of [X] = 1/ years. The exponential pdf fX(x) = e−x for x ≥ 0, and zero elsewhere. Find the probability of the next eruption occurs before next 2 years, P(x < 2) =?

0.9975

Step-by-step explanation:

check  the attached files below

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: