1. A sample of 25 observations is taken from a normal population with a standard deviation of 12. The sample mean is 37. Determine the 95% confidence interval for the population mean.

Confidence interval for the population mean ........ isand ..........

1. Determine the mean, median, and standard deviation of the following frequency distribution:

ClassFrequency

0 to under 5 1

5 to under 10 4

0 to under 15 11

15 to under 20 6

20 to under 25 5

Mean: ?

Median: ?

Standard deviation: ?

1. Compute the mean and variance of the following discrete probability distribution:

XP (X)

3 0.4

7 0.2

9 0.4

Mean?Variance?

1. All Seasons Plumbing has two service trucks which frequently break down. The probability the first truck is available is 0.75, the probability the second truck is available is 0.47, and the probability that both trucks are available is 0.38:

What is the probability neither truck is available?

Probability