1.A random sample of size n=19 is obtained from a normally distributed population with a population mean of =100 and a variance ^2=20. What is the probability that the sample variance is greater than 55?

The probability is

a.between 0.025 and 0.05

b.between 0.01 and 0.025

c.less than 0.001

d.between 0.001 and 0.01

e.between 0.05 and 0.1

f.greater than 0.1

2.Monthly rates of return on the shares of a particular common stock are independent of one another and normally distributed with a standard deviation of 2.1. A sample of 12 months is taken.

a. Find the probability that the sample standard deviation is less than 2.6.

The probability is

between 0.99 and 0.999

between 0.975 and 0.99

between 0.9 and 0.95

between 0.95 and 0.975

greater than 0.999

less than 0.9

b. Find the probability that the sample standard deviation is more than 1.1.

The probability is

between 0.95 and 0.975

between 0.975 and 0.99

between 0.99 and 0.999

between 0.9 and 0.95

greater than 0.999

less than 0.9

3.A production process manufactures electronic components with timing signals whose duration follows a normal distribution. A random sample of 7 components wastaken, and the durations of their timing signals were measured.

a. The probability is 0.05 that the sample variance is bigger than what percentage of the populationvariance?

b. The probability is 0.10 that the sample variance is less than what percentage of the populationvariance?

a. The probability is 0.05 that the samplevariance, expressed as a percentage of the populationvariance, is greater than or equal to %.

(Round to the nearest hundredth asneeded.)

b. The probability is 0.10 that the samplevariance, expressed as a percentage of the populationvariance, is less than or equal to %

(Round to the nearest hundredth asneeded.)