Question

1. Does the order in which wine is presented to a customer make a difference? In one Canadian study, subjects were asked to taste two wine samples in sequence and then indicate which was preferred. Both samples given to a subject were actually the same wine, although subjects were expecting to taste two different samples of a particular variety.

The study was looking to make an inference on the proportion of all Canadian adult wine drinkers who would select the wine presented first. The researchers found 32 volunteers to participate in their study.

1. If the researchers had wanted to estimate the proportion of all adult Canadian wine drinkers who would select the wine presented first to within 0.10 using a 95% confidence interval, how many subjects would they have needed? You may use the value of p.

Answer 1

given data,
n one Canadian study, subjects were asked to taste two wine samples in sequence and then indicate which was preferred.
Both samples given to a subject were actually the same wine, although subjects were expecting to taste two different samples of a particular variety.
sample proportion is 50%
margin of error is 0.10
confidence level is 95%
sample size is number of subjects
If the researchers had wanted to estimate the proportion of all adult Canadian wine drinkers
who would select the wine presented first to within 0.10 using a 95% confidence interval,

a.

Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.05 is = 1.96
Sample Proportion = 0.5
ME = 0.1
n = ( 1.96 / 0.1 )^2 * 0.5*0.5
= 96.04 ~ 97