solution

A quality control engineer is interested in estimating the proportion of defective items coming off a production line. In a sample of 360 items, 46 are defective. Calculate a 90.0% confidence interval estimate for the proportion of defectives from this production line. (Use 3 decimal places in calculations and in reporting your answers.)
Lower Limit:
Upper Limit:

Part 2: A quality control engineer is interested in estimating the proportion of defective items coming off a production line. In a sample of 387 items, 45 are defective. Calculate a lower confidence limit for a 90.0% confidence interval for the proportion of defectives from this production line. (Use 3 decimal places in calculations and in reporting your answer.)

Part 3: A prison official wants to estimate the proportion of cases of recidivism. Examining the records of 197 convicts, the official determines that there are 108 cases of recidivism. Find the standard error for the population proportion of cases of recidivism. (Round to 3 decimal places.)

Part 4: The head of a computer science department is interested in estimating the proportion of students entering the department who will choose the new computer engineering option. A preliminary sample indicates that the proportion will be around 0.23.
What size sample should the department head take if she wants to be 95% confident that the estimate is within 0.02 of the true proportion?

Part 5: A prison official wants to estimate the proportion of cases of recidivism. Examining the records of 169 convicts, the official determines that there are 98 cases of recidivism. Find a point estimate of the population proportion of cases of recidivism. (Round your answer to three decimal places.)