The Castaic Lake reservoir provides water for the northern portion of the Greater Los Angeles Area. A random sample of days during Summer 2013 was obtained and the capacity of the lake on each day (in...

The Castaic Lake reservoir provides water for the northern portion of the Greater Los Angeles Area. A random sample of days during Summer 2013 was obtained and the capacity of the lake on each day (in thousands of acre feet) was measured.76 WATER

 a. Suppose the historic mean capacity during the summer is 277 thousand acre feet. Is there any evidence to suggest that the true population mean capacity has decreased? Assume normality and use a = 0.05.

b. Find the p value associated with this hypothesis test.

The Liberty Stone Vista standard unit is manufactured to weigh 70 pounds.77 This double-sided stone is part of a wall system for residential and commercial retaining walls. Large variability in the weight of these stones could cause structural deficiencies in a wall. A random sample of 17 standard units was obtained and the sample variance was 7.75 pounds2 .

a. Is there any evidence to suggest that the population variance is greater than 4 pounds2 ? Assume normality and use a = 0.05.

b. Find bounds on the p value for this hypothesis test.