Explain what the phrase 87% confident meats when we interpret an 87% confidence

Question

Explain what the phrase 87% confident meats when we interpret an 87% confidence interval for some population proportion. (a) 87% of similarly constructed intervals would contain the value of the sample proportion. (b) 87% of the observations in the population fall within the bounds of the calculated interval. (c) The probability that a sample proportion falls in the calculated interval is 0.87. (d) In repeated sampling, 87% of similarly constructed intervals would contain the value of the population proportion. If we want to change n standard error from 15 to 5 by changing the sample size, we need to multiply the original sample size by ________. (a) 9 (b) 3 (c) 1/3 (d) 1/9 A manager at the Papyrus Paper Company wants to estimate the mean time required for a new machine to produce a ream of paper. A random sample of 36 reams required an average machine of 1.5 minutes for time each ream. Assuming sigma = 0.30 minute, construct an interval estimate with a confidence level of 90 percent. (a) 1.5 plusminus 0.0980 (b) 1.5 plusminus 0.0823 (c) 1.5 plusminus 0.4935 (d) 1.5 plusminus 0.1502

Explanation / Answer

1) option D is correct

2)as std error is inversely proportional to square root of sample size

hence option a is correct

3)for 90% CI, z=1.645

std error =std deviation/(n)1/2 =0.05

hence confidence ievel =sample mean -/+z*std error

option B is correct

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.