In: Statistics and Probability
8. A survey of 300 Canadian online shoppers was conducted. In response to the question of what would influence the shopper to spend more money online in 2012, 18% said free shipping, 13% said offering discounts while shopping, and 9% said product reviews. Construct a 95% confidence interval estimate of the population proportion of online shoppers who would be influenced to spend more money online in 2012 with:
a. Free shipping.
b. Discounts offered while shopping.
c. Product reviews
Solution:
a. The 95% confidence interval for free shipping is:
Where:
is the critical value at the 0.05 significance level.
Therefore, the 95% confidence interval estimate of the population proportion of online shoppers who would be influenced to spend more money online in 2012 with free shipping is
b. The 95% confidence interval for Discounts offered while shopping is:
Where:
is the critical value at the 0.05 significance level.
Therefore, the 95% confidence interval estimate of the population proportion of online shoppers who would be influenced to spend more money online in 2012 with Discounts offered while shopping is
c. The 95% confidence interval for a product review is:
Where:
is the critical value at the 0.05 significance level.
Therefore, the 95% confidence interval estimate of the population proportion of online shoppers who would be influenced to spend more money online in 2012 with a product review is