Aresearcher believes that 12% of a simple random sample of adults will be able to identify a toyota scion by brand and model name. the researcher wishes to estimate with 95% confidence and an allowance for error no greater than 2.5%. how large should the sample be?

650

Step-by-step explanation:

When prior estimate of population proportion is known , then the formula to find the required sample size is given by :-

, where p= population proportion

E= margin of error

z* = Critical value.

Let p be the proportion of adults able to identify a Toyota Scion by brand and model name.

As per given , we have

p = 12%= 0.12

E= 2.5%=0.025

Critical value for 95% confidence interval : z* = 1.960  [By z-table ]

Then, the required sample size =

Thus , the required sample size = 650