Answers

1. a) 99% is wider

b) You are 95% confident that the interval contains the parameter.

c) The standard error of the mean is proportional to 1/sqrt(n) where n is the sample size.

2.a)Pr(X>34) = .2514

b) Pr(xbar > 34) = .0228

c) Pr(xbar > 32 or xbar < 28) = .1836

3.a) Pr(X>20)=.4443 use normal approx to binomial and continuity correction

b) need 86 animals captured (85.36)

4. a) (4785.2 < m < 5792.58) use t distribution

b) need 46 pipes in the sample (45.103)

4. a) (6.495 < s ² < 18.506)

b) (2.549 < s < 4.302)