STAB22H3 Chapter Notes - Chapter 22: Standard Deviation, Null Hypothesis, Confidence Interval

• School: UTSC
• Department: Statistics
• Course: STAB22H3
• Professor: Srishta Chopra

Document Summary

The variance of the sum or difference of two independent random variables is the sum of their variances. Var (x y) = var (x) + var (y) so sd (x - y) = sd2(x )+sd2(y ) = The standard deviation of the difference between two proportions: The standard deviation of the sample proportions are: Sd ( ^p1)= p1 q1 n1 and sd ( ^p2)= p2 q2 n2. The variance of the difference in the proportions is: +( p2 q2 n2 )2 p1 q1 n1 p2 q2 n2. The standard deviation is the square root of the variance: Independent groups assumptions: the two groups being compared must also be independent of each other. The sampling distribution model for a difference between two independent. Provided that the sampled values are independent, the samples are independent, and the sample sizes are large enough, the sampling distribution of ^p1 ^p2.