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Homework #2

1. The lengths of time bank customers must wait for a teller are normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute.

a. What proportion of bank customers waits between 2 and 4 minutes

b. What percentage wait more than 3.5 minutes?

c. What proportion waits between 2.0 and 3.5 minutes?

d. What percentage wait less than 2 minute?

2. The area under the standard normal distribution between -2.0 and 2.5 is

a. 0.1338

b. 0.1668

c. 0.4332

d. None of the above

3. Use the data in the chart below to solve your quiz answers.

Quiz 1

Mean – 93.86

s – 8.79

1. What was your score on Quiz 1? If it was 100, replace it with an 85.

Score was 70%

2. Convert your Quiz 1 score to a z-score. List your z-score.

Score was 70%

3. What percentage of the class did better than you?