MATH 203 Sample Problem Unit 3
Bottles of liquid soap are normally distributed in weight with a mean of 64 ounces and a
standard deviation 0.5 ounces.
(a) Let various random samples of size 21 be collected. Compute P(0.47 ≤S≤0.55).
(b) Suppose is unknown, but a random sampling of 26 bottles yields
S
= 0.60. Find a
95% confidence interval for the true standard deviation.
(c) Using
S
= 0.60 from a sample of 26 bottles, is there evidence, at the 10% level of
significance, to reject the claim that = 0.5? State null and alternative hypotheses, give
the test-statistic and
P
-value, and use the
P
-value to explain your conclusion in detail.