a) The case information stated that 66% of teenagers purchase products that reflect their style and image as being hip and trendy. How would you test the appropriateness and validity of that percentage? In a test where 900 teens are randomly selected across Canada, 625 state that they purchase products that reflect their style/image as being hip and trendy. Test the claim made in the case regarding the purchase of products by teenagers reflecting their style and image. Use a significance level of 5% to help you reach a suitable statistical decision. What would be the probability of discrediting the claimed percentage (of 66%) if in fact it were true?
b) Historically, it has been verified that 72% of all teens that ate frozen pizza were girls. Due to apparent changes in gender tastes, it is believed that more teen boys are now eating frozen pizzas. From a random sample of 653 teens that eat frozen pizza, 513 are girls. Does this sample result provide sufficient evidence to conclude that a higher proportion of teenage girls than before eat frozen pizza?
c) What is the proportion of the teenage population that watches advertisements on television? It has been claimed by a reputable source that, historically, this proportion has been in the neighbourhood of 0.87. McCain researchers want to test whether this figure is true. A random sample of 612 teens is selected. The results of the hypothesis-testing procedure are shown below. Analyze the results shown in the output below, and discuss and explain its contents, as well as any subsequent implications this sample study might have on the behavioural spending patterns of the teenage population as a result of television advertising viewings. To perform this analysis, use alpha = 0.05.
Test of p = 0.87 versus. p does not = 0.87
x = 490
n = 612
sample p = 0.800654
95% CI (0.769002, 0.832306)
Exact p value 0.0035