This the 1st question of 51 or Statistics for engineers and

This the 1st question of 5.1 or Statistics for engineers and scientists (4th edition).

- Find the value of z?/2 to use in expression (5.1) to construct a confidence interval with level

a) 99%

b) 90%

Show steps please.

Solution

(a) Given a=1-0.99=0.01, Z(0.005) = 2.58 (from standard normal table)

--------------------------------------------------------------------------------------------------------------------

(b) Given a=1-0.9=0.1, Z(0.05) =1.65 (from standard normal table)