1251 WordsMay 30, 20136 Pages

Submit completed tests as word or pdf files via email to paul.kurose@seattlecolleges.edu
Due: Sunday, May 19 (by 8am).
1. a) In Chapter 6, you learned to find interval estimates for two population parameters, a population mean and a population proportion. Explain the meaning of an interval estimate of a population parameter.
An interval estimate for a specified population parameter (such as a mean or proportion) is a range of values in which the parameter is estimated to lie. In Chapter 6, you were assigned to find interval estimates for a population mean and a population proportion. b) Is finding an interval estimate an example of inferential or descriptive statistics? Explain.
It is an interval estimate is an example of*…show more content…*

Explain your reasoning. The confidence level will increase the margin of error of a Confidence-interval estimate.
d) If confidence level is kept constant, what effect will an increase in sample size have on the margin of error of a confidence interval estimate? Explain your reasoning. An increase in sample size will decrease the margin of error of a
Confidence-interval estimate.
3. a) A simple random sample of thirty-six students has a mean age equal to 25 years. Given =4.8 years, determine a 90% confidence interval estimate for µ. E ≤0.8, µ = 25 so The 90% confidence interval is 25 ± 1.32 = 23.68 and 26.32
b) Determine the sample size required to have a (smaller) margin of error of 0.8 years for a (higher) 95% confidence level for the confidence interval estimate for µ in part a) above. The sample size should be n ≥ 138.3 ≈ 139 for a 95% confidence level
4. A) In a simple random sample of students from colleges across the state of Washington, 490 are in favor decreasing the size of their college administration and 310 are not. Determine a 95% confidence interval estimate for the proportion of Washington college students who favor decreasing the size of their college administration. With a 95% confidence, I can say the proportion of Washington college students who favor decreasing the size of their college administration

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