1. The lengths of time bank customers must wait for a teller are normally distributed, with a mean of 2.5 minutes and a standard deviation of 1 minute.

1. What proportion of bank customers waits between 3 and 4.25 minutes
2. What percentage wait more than 4 minutes?
3. What proportion waits between 1 and 3.25 minutes?
4. What percentage wait less than 1 minute?

2.  To estimate the medical charges for an appendectomy Blue Star Insurance has data from a random sample of 60 patients.  The sample mean cost is $420, with a sample standard deviation of $80. Construct a 95% confidence interval for the population mean cost.

We are 95% confident that the populations mean costs of patients' medical charges for an appendectomy through Blue Star Insurance range is between _____________ and ________________

3.

A group of voters from 3 states were selected and the results are above.

What is the probability of selecting a random voter from Chicago, given that the voter was a republican?

a).357

b).417

c).267

d).200

4.

A group of voters from 3 areas were selected and the results are above.

What is the probability of selecting a random voter that is from Detroit or a Republican?

a).093

b).520

c).613

d).357

5. There is a bag with 62 balls.  31 are yellow and 31 are red.  In 20 pulls from the bag, 20 balls are red.  What is the probability with replacement that the 21^st pull will be red?

a) .5000

b) .2500

c) .000000477

d) .03125

e)  None of the above