Question

QUESTION 15 A statistician employed by a consumer testing organization reports that at 95% confidence he has determined that the true average content of the Uncola soft drinks is between 12.714 to 13.286 ounces, but he forgot to report the size of the sample he had selected. Assuming the standard deviation of the population is 1.21, determine the size of the sample. (NOTE: ROUND YOUR ANSWER TO THE NEAREST INTEGER) QUESTION 16 If the population variance of the lifetime of a vacuum cleaner is 900 hours, how large of a sample must be taken in order to be 95 % confident that the margin of error will not exceed 5 hours?

Answer 1

Question IS in this he true aveage Conteut 12.714 avd 13.286 Ihe uincola Soft drinks is helaseen UPper value = 13286 lower value 13. 286-12.14 U-L Margin of error CE) O 286 2 95. Confidence Tntenal Cibical value zZalp. = o.05 = -o025 ol1-095 2 o.0S =1.96 CFYom z-table Eample Siae n) = Gven data E 12 .96 .2 O. 286 (n)=68.76 Somple siae u) 69 estien 6 from data Populaton voriance S 95. Confidence Intenal critital value Z (From -table =1.96 Zoo25 Maxgin of enor (E)= 5 레오*S Sample size cn) (1.96)900) (n)= 138.2976 |138 Sample size cn)