A manufacturer of fitness equipment inspects a random sample of the welds that are performed on various pieces of equipment in an effort to monitor the quality and strength of the equipment. During one week, a random sample of 200 welds showed that 15 of the welds were defective. 4) Which of the following represents a 98% confidence interval for the population proportion of defective welds? (Round your answer to 3 decimal places.)

A) [.056, .094] B) [.032, .118] C) [.064, .086] D) .037, .112] E) [.072, .078] 5)

5)The production manager decides that a 95% confidence interval will be suitable, but he would like the margin of error in the interval to be no more than .035. What sample size should he use for the computation of the sample proportion of defective welds?

A) 817 B) 409 C) 1156 D) 578 E) 29

6) The production manager states that he has computed a 95% confidence interval for the population proportion of defective welds, and that "the margin of error is .035." Which of the following is an appropriate interpretation for the margin of error in this case?

A) He is 95% confident that the population proportion is within .035 of the sample proportion he computed.

B) He is 95% confident that the population proportion is .035.

C) The population proportion cannot differ from the sample proportion by more than .035 in either direction.

D) The sample proportion he computed is within .035 of the population proportion. E) He is 95% confident that the population proportion is between 0 and .07.