Question

Question Heip Detemmine the sample size needed to construet 99% confidence interval to emate the aveage GPA for the student popuaion at a colege within 06 GPA points Assume the standard deviaion of the GPA for the student populaton is 3.0 The sample size needed is (Round up to the neaest integer)

Answer 1

Ans Grun that Con ficknce levcl 7 and Desired Mavqin of ErrOY, Eo-6. r PC 15-u1E)2- -u Zol/2xo nz Margin of ETOY length of CI) 2 devfation )= Stancasd 1- con falence Signfcance leuel =I-o-99 The Crtical value Zoo05 2 58 frorn -table 1 2 Zo.005 X 2.587 166.4 166

in teger, n has to be minimum Sintc the number a bove take the cefling of and get n =166 e a different get dakc exact 2-value, we wil nte calcolationw be answer the exact 2.575829 3035489 x 3 2 n =165. 872 O.6 This roond P to n 239 ALso, Some Critica Prefer usng 2. 575 wich gve 65- 85 65 peoplc valwe Sample sTte should be atleast n= erthe 66 or 165