Consider the county of the previous exercise and suppose that a simple random sample of 4 males and a simple random sample of 4 females are collected, independently of one another. (a) what is the sample space and the probability model for this random experiment? (b) what is the probability that exactly 4 of the 8 selected voters are democrats? hint: observe that {4 democrats} = [ 4 i=0 { i male democrats and 4 − i female democrats} .

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.