1.A jar contains 30 black marbles, 40 white marbles, and 10 blue marbles.

a.If you randomly select a marble from the jar, what is the probability that you will get a white marble?

b.If you are selecting a random sample of marbles and the first 2 marbles are both white, what is the probability that the third marble will be black? (Hint: random sample requires sampling with replacement)

1. A bag of candy contains 20 caramels, 35 chocolates, and 45 mints.

a.What is the probability that I will draw a caramel or a chocolate?

b.Suppose I draw two pieces of candy, replacing the first before drawing the second. What is the probability that I will draw a mint of the first trial and a mint on the second?

c.What is the probability over two trails (sampling with replacement) I will draw one caramel and one chocolate, ignoring the order in which they are drawn?

1. The distribution of scores on the SAT is approximately normal with and .

a.What proportion of the population have SAT scores above 475?

b.What proportion of the population have SAT scores below 400?

c.What is the minimum SAT score needed to be in the highest 15% of the population?

d.What SAT score separates the top 65% from the rest of the distribution?

1. A normal distribution has a mean of with . Find the following values:

a.The 25^th percentile

b.The 77^th percentile

c.The percentile rank for X=160

d.The percentile rank for X=96

e.The semi-interquartile range

1. A trick coin has been weighted so that the probability of heads is 0.8 and the probability of tails is 0.2.

a.If you toss the coin 100 times, how many heads would you expect on the average?

b.What is the probability of obtaining more than 92 heads in 100 tosses?