Question

A quality-conscious disk manufacturer wishes to know the fraction of disks his company makes which are defective. Step 2 of 2 : Suppose a sample of 1762 floppy disks is drawn. Of these disks, 70 were defective. Using the data, construct the 90% confidence interval for the population proportion of disks which are defective. Round your answers to three decimal places.

Answer 1

Solution Given thet 1762 X = 70 SO 70 P : 0.040 X 1762 Point estim ate O.O40 I P I O.04o 0.96 9 o7. Confidonce AH Z is level or -9o . 1-0.9 =0. 1 /2 0.0 5 Z&12 Zo.05 1.645 EC1-P Maigin of EOn = I.645 O.a407 0.9 6 176 2 O.008 A gov. Confidence interval Pis P-EXPP +E 0.040-0.o08 P< O.040 to.o08 O. o 3 2 P 0.048 C0.032,0.048