A marketing research company is estimating which of two soft drinks college students prefer. A random sample of 330 college students produced the following 95% confidence interval for the
Proportion of college students who prefer one of the colas: (.330, .469). What additional
Assumptions are necessary for the interval to be valid?
A)The sample was randomly selected from an approximately normal population.
B)The population proportion has an approximately normal distribution.
C)No additional assumptions are necessary.
D)The sample proportion equals the population proportion.

Question

Quizplus · Accepted Answer

The confidence interval is based on the assumption that the sample is random and large enough for the Central Limit Theorem to apply, which makes the sampling distribution of the sample proportion approximately normal. No additional assumptions are necessary beyond those already stated.

A Marketing Research Company Is Estimating Which of Two Soft