Week5 Discussion Constructing Confidence Intervals
Each week, you will be asked to respond to the prompt or prompts in the discussion forum. Your initial post should be 75-150 words in length, and is due on Sunday. By Tuesday, you should respond to two additional posts from your peers.
Watch this video: https://www.youtube.com/watch?v=tFWsuO9f74o
- What is a confidence interval?
- Let’s say you made a confidence interval for a mean taken from the sample that is representative of the population. Will that confidence interval apply to the population or to the sample?
- In the discussion for week 4, you rolled a pair of dice 10 times and calculated the average sum of your rolls. Then you did the same thing with 20 rolls. Use your results from the week 4 discussion for the average of 10 rolls and for the average of 20 rolls to construct a 95% confidence interval for the true mean of the sum of a pair of dice (assume s = 2.41).
- What do you notice about the RANGE of the interval for the mean of 10 rolls versus the mean of 20 rolls? Finish this rule: As the samples size increases, the range of the confidence interval ______________ (increases/decreases – pick one).
- Using your mean for 20 rolls, calculate the 90% confidence interval. Compare the range of the confidence interval for 90% to 95%. Finish this rule: As the confidence level increases, the range of the confidence interval _______ (increases/decreases – pick one).
- In the project for this week, you are calculating confidence intervals for someone who is picking between the engineering major and the business major. You are trying to tell him/her what is likely to happen. Is it more helpful to have a large range or a narrow range in a confidence interval? Why?