Sec_8_solutions__10_29_04_

# Sec_8_solutions__10_29_04_ - CEE 304 Section#8 Example...

• Notes
• 4

This preview shows pages 1–3. Sign up to view the full content.

1 CEE 304 Section #8 Example Problems (10-26-04) Confidence Intervals for Small Samples: 1. An environmental engineer is studying the concentration of organics in a groundwater source for a rural water supply. Twelve samples yielded a sample mean and variance of 24.3 µ g/l and 81 ( µ g/l) 2 , respectively. a.) Construct a 99% confidence interval for the true mean concentration of organics in this source of water assuming individual observations have a normal distribution. b.) What is the probability the true mean value is contained in the particular interval you just calculated? 2. The sample average ultimate tensile strength for a sample of 35 high-strength magnetic alloy steel rings used in turbine generators was 152.3 ksi, while the sample standard deviation was 4.8 ksi. Obtain a 99% confidence interval for the true average tensile strength of such rings.

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

2 Hypothesis Testing Example ° Devore, Sec. 8.1, #11 The calibration of a scale is to be checked by weighing a 10-kg test specimen 25 times.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern