1. A random sample of size n=19 is obtained from a normally
distributed population with a population mean of μ=100 and a
variance σ2=20. What is the probability that the sample variance is
greater than 45?
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 1.7. A sample of 12 months
is taken.
a. Find the probability that the sample standard deviation is
less than 2.6.
b. Find the probability that the sample standard deviation is
more than 1.1.
3. production process manufactures electronic components
with timing signals whose duration follows a normal distribution. A
random sample of 11 components was taken, and the durations
of their timing signals were measured.
a. The probability is 0.01 that the sample variance is bigger
than what percentage of the population variance?
b. The probability is 0.10 that the sample variance is less than
what percentage of the population variance?
a. The probability is 0.01 that the sample variance,
expressed as a percentage of the population variance, is
greater than or equal to ---------%.
(Round to the nearest hundredth as needed.)
b. The probability is 0.10 that the sample variance,
expressed as a percentage of the population variance, is less
than or equal to ------------%
(Round to the nearest hundredth as needed.)