Find the unique least squares solutions of the following systems of equations. (a) x+ y = 1 -x+2y = 0 3x+4y = 6 (b) x- y = 4 x+ 2y = -1 2x-3y = 3

Lecture 10: Inference about population proportions: We want to move from studying the mean of a sample/population to studying the proportion of a sample/population having some property. Sampling distribution of a sample proportion: Take an SRS of size n from a large population that contains proportion p of successes. Let ˆp be the sample proportion of successes number of successes∈thesample pˆ= n The mean of the sampling distribution is p. p(1−p) the standard deviation of the sampling distribution is r ) √¿ p(1−p ) For large n