STAT 1000Q Lecture Notes - Lecture 20: Confidence Interval, Standard Deviation, Blood Pressure

• School: UConn
• Department: Statistics
• Course: STAT 1000Q
• Professor: Robert Apruzese

Document Summary

Inference on the difference of 2 population means. Based on if they are independent or not. Comparison of the mean sat scores of college freshmen in ct with those of college freshmen in ma. Comparison of average miles per gallon for hondas vs toyotas. 2 measurements are collected from each member in a single population. Blood pressure from a person both before and after medication. Tire treads on a car- one left tire and one right tire. For independent populations (x1-x2) +/- (cid:894)) alpha/(cid:1006)(cid:895) x (cid:894)sd(cid:1005)(cid:894)s(cid:395)ua(cid:396)ed(cid:895)/(cid:374)(cid:1005) + sd(cid:1006)(cid:894)s(cid:395)ua(cid:396)ed(cid:895)/(cid:374)(cid:1006)(cid:895)(cid:895) Create a 95% confidence int for the difference of sat scores in ct vs ma. Sd2= 116 (513-526) +/- (cid:1005). (cid:1013)(cid:1010) x (cid:894)(cid:1005)(cid:1005)(cid:1004)(cid:894)s(cid:395)ua(cid:396)ed(cid:895)/(cid:1005)(cid:1006)(cid:1009) + (cid:1005)(cid:1005)(cid:1010)(cid:894)s(cid:395)ua(cid:396)ed(cid:895)/(cid:1005)(cid:1009)(cid:1004)(cid:895) 13 +/- 26. 77 (-39. 77, 13. 77) so point estimate is -13 and error is 26. 77. Includes a negative so cannot draw a conclusion. Test to see if small cap stocks are more volatile on average than large cap stocks.