{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

320_hw8_ans

# 320_hw8_ans - Economic Statistics Homework 8(Estimation...

This preview shows pages 1–2. Sign up to view the full content.

Economic Statistics: Homework 8 (Estimation) Interval Estimation of Population Mean: Variance Known 1. A random sample of sixteen observations from a normal population with standard deviation of 6 had mean 25. Find a 90% confidence interval for the population mean, μ. n = 16, σ = 6, X = 25, 1 - α = 0.90 Since the population is normal, we can use Z since σ is known SMPER = n Z / 2 / σ α = 1.645 (6 / √16) = 2.4675 Interval: 25 +/- 2.4675; 22.5 to 27.5 2. A process produces bags of refined sugar. The weights of these bags are normally distributed with standard deviation 1.2 ounces. The contents of a random sample of twenty five bags had mean weight 19.8 ounces. Find a 95% confidence interval estimate of the true mean weight (population) for all bags of sugar produced by the process. Population is normal, σ known, we use Z. n = 25, σ = 1.2, X = 19.8, 1 - α = 0.95 SMPER = n Z / 2 / = 1.96 (1.2 / √25) = 0.4704 Interval: 19.8 +/- 0.47; 19.33 to 20.27 Interval Estimation of Population Mean: Variance Unknown

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 2

320_hw8_ans - Economic Statistics Homework 8(Estimation...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online