3.28 chickenpox, part ii. we learned in exercise 3.26 that about 90% of american adults had chickenpox before adulthood. we now consider a random sample of 120 american adults. (a) how many people in this sample would you expect to have had chickenpox in their childhood? and with what standard deviation? (b) would you be surprised if there were 105 people who have had chickenpox in their childhood? (c) what is the probability that 105 or fewer people in this sample have had chickenpox in their childhood? how does this probability relate to your answer to part (b)?

step-by-step explanation:

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:

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right

  or  

step-by-step explanation:

if the four friends split the cost, p, of the pizza evenly, then each friend pays one-fourth of the cost of the pizza.

the expression is   or