ECON2209 Lecture 23: 27March_EconStats_Karagodsky
Document Summary
Q2 you are a pharmaceutical sales rep making independent calls. P ( p < . 24) p ( p < . 22) Q2. 2 find 99% con dence interval of out of 20 calls 8 are successful. Setup: 1 = 99, = 1, n = 20, p = 8/20 = . 4. 2r p(1 p) n or p zn 1, . 2r p(1 p) n we will use the right one because we don"t know population std. , and t19,. 5% = 2. 861<= from chart n. Q2. 4 how large would sample size need to be for 95% acceptance to be bellow . 2196 when p of a successful call = . 2. If the acceptance interval is given by [ lowerbound , upperbound ] then the upperbound needs to be below . 2196. p z . 2r p(1 p) n should be p + z r p(1 p) n. < . 0001 n 1600 n must be at least 1600. 2. 5 suppose out of 100 calls, 11 are successful.
