In this exercise, you will derive and use a "bootstrap Z" interval.
(a) Following the steps in the derivation of the bootstrap t interval in Section 7.5, derive a bootstrap Z interval for μ, for cases when σ is known.
(b) Calculate this interval for the Verizon CLEC data; for σ, use the sample variance of the Verizon ILEC data. (In practice, we may use methods for known σ when we can estimate σ from a large related data set.)
(c) Compare that interval with a formula z interval. How does the bootstrap Z interval adjust for skewness?