HOMEWORK 27.) A. 1.7898 0.0173 28.) A. 1.796 2.045 1.333

30.) A. SRS, Normality, and independence. All conditions are satisfied. B. We are looking for the mean vitamin C content of the CSB. (16.487, 28.513) We are 95 % confident that the mean vitamin C content is between 16.487 and 28.513.

Homework 31.) A. Slightly skewed left with mean of 18.48 and standard deviation of 3.12. Yes; the sample size is not large enough to use the CLT, but there are no outliers or severe skewness. Mean=18.48, s=3.12, std. error=0.6977, margin of error=1.46 (17.02, 19.94) We are 95% confident that the mean mpg for this vehicle is between 17.02 and 19.94. No, gas mileage is dependent on many factors so it is unlikely that this one vehicle is representative of other vehicles.

Paired t Procedures Section 10.2 Day 2

Paired t Procedures Used for matched pairs design Looking for the mean difference in response to 2 treatments or mean difference between before and after treatments Not usually an SRS, so you CANNOT generalize to the entire population However random assignment of treatment allows us to compare treatments.

EXAMPLE: Comparing Dominant vs. Non-dominant Use your calculator to randomly determine which hand will go first. 1-dominant; 2-non-dominant When I say go, you are going to write as many A’s as many times as you can in 30 seconds. We will repeat with the other hand.

Example: Construct a 99% confidence Interval for this data.

DEFINITION: Robust: calculations remain fairly accurate when a condition has been violated Are t procedures robust against outliers? (Will outliers change your results dramatically?)

Using t Procedures Except in small sample sizes, the assumption of an SRS is more important than Normality n<15: use t procedures if the data is close to Normal. (no outliers and roughly symmetric) n>15: use t procedures except in the presence of outliers or strong skewness n>30: You can use t procedures even for clearly skewed distributions (by CLT)

Homework: Pg. 657 #34-36