Question

Determine the z value used to build a 90% confidence interval estimate of the population proportion. Give the positive value answer exactly as found from tables (three decimal places).

Answer 1

Z critical value for 90% confidence.

Here exact p value of 0.05 is not found in table. At z is 1.64 p value is 0.0505 which is rounded to 0.05 and z value 1.64 is taken as our required critical value.

Z critical value is 1.640