Question

A research group conducted an extensive survey of 2857 wage and salaried workers on issues ranging from relationships with their bosses to household chores. The data were gathered through hour-long telephone interviews with a nationally representative sample. In response to the question, "What does success mean to you?" 1470 responded, "Personal satisfaction from doing a good job." Let p be the population proportion of all wage and salaried workers who would respond the same way to the stated question. Find a 90% confidence interval for p. (Round your answers to three decimal places.)

lower limit
upper limit

Answer 1

n = 2857

x = 1470

                     (Round to 4 decimal)

90% confidence interval for population proportion (p):

Confidence level = c= 0.90

Lower limit =

Upper limit =

Where

Where Zc is z critical for (1+c) /2 = (1+0.90)/2 = 0.95

Zc = 1.645            (From statistical table, average of 1.64 and 1.65)

E = 0.0154                         (Round to 4 decimal)

Lower limit = 0.5145 - 0.0154 = 0.4991

Upper limit = 0.5145 + 0.0514 = 0.5659

Lower limit = 0.4991

Upper limit = 0.5659