Reference no: EM132184465

Determine the sample size needed to obtain an estimate of µ if the margin of error E = 0.11, σ = 0.95, and the confidence level is 99% (use z_0.005 = 2.57).

Alternatively, To obtain z from a graphing calculator, we use the formula z = invNorm(1 - α/2, µ, σ) where µ is the mean and σ is the standard deviation of the normal distribution. For the standard normal distribution µ = 0 and σ = 1. Recall that in general z = invNorm("area to left of z", µ, σ).

It is given that E = 0.11 and σ = 0.95.

(a) Find α for 99% confidence level.

α = 

(b) Find 1 - α/2.

1 - α/2 = 

(c) Find z_α/2 for a 99% confidence level.

z_α/2 =