This file of MATH 221 Week 6 DQ Confidence Interval Concepts comprises:
1. Find the margin of error for the given values of c = 0.95 , s= 3.6 and n= 36
(Round to three decimal places as needed)
STUDY PLAN: 6.1.13, 6.1.15
OBJECTIVE: CONSTRUCT AND INTERPRET CONFIDENCE INTERVALS FOR THE POPULATION MEAN
2. You are given the sample mean and the sample standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Which interval is wider? If convenient, use technology to construct the confidence intervals.
A random sample of 37 gas grills has a mean price of $637.70 and a standard deviation of $58.30
(Round to one decimal place as needed)
STUDY PLAN: 6.1.35, 6.1.36, 6.1.37, 6.1.40
OBJECTIVE: DETERMINE THE MINIMUM SAMPLE SIZE
3. A doctor wants to estimate the HDL cholesterol of all 20- to 29- year-old females. How many subjects are needed to estimate the HDL cholesterol within 4 points with 99% confidence assuming standard deviation sigma = 19.4? Suppose the doctor would be content with 90% confidence. How does the decrease in confidence affect the sample size required?
(Round to the next whole number)
STUDY PLAN: 6.1.53, 6.1.56
OBJECTIVE: FIND A CRITICAL VALUE
4. Find the critical value tc for the confidence level c= 0.80 and sample size n= 17
(Round to the nearest thousandth as needed)
STUDY PLAN: 6.2.1, 6.2.3
OBJECTIVE: CONSTRUCT AND INTERPRET CONFIDENCE INTERVALS FOR THE POPULATION MEAN
5. The monthly incomes for 12 randomly selected people, each with a bachelor
