Question

A marketing research firm is estimating which of two sodas (A or B) college students prefer. A random sample of 75 college students was chosen in which 45 preferred Soda A. Is this sample large enough to calculate a confidence interval?

Answer 1

Explanation:

Given that a marketing research firm is estimating which of two sodas (A or B) college students prefer.

Sample size of 75 was taken at random.

Since sample size is sufficiently large i.e. >30, and also since samples are taken at random, we can assume that sample proportion

p=
`(45)/(75) =0.6` follows a normal distribution with mean = 0.6 and variance = npq = 75(0.6)(0.4)

Yes, this sample is large enough to calculate a confidence interval.