In this discussion you'll look at a few situations and think about whether causation may or may not exist. Some of the scenarios below indicate the possibility of cause and effect, and some don't. A study of 50 cities in North America finds a strong correlation (r = .75) between the number of teachers employed in a city and the dog food sales in the city. Are the teachers encouraging people to buy dog food? Are there any other factors or causes to consider?

A study of 30 developing nations finds a strong correlation (r = .82) between the number of radio stations per capita and the number of new cancer cases reported each year. Do radio stations cause cancer? Are there any other factors or causes to consider?

Abottled water distributor wants to estimate the amount of water contained in 1-gallon bottles purchased from a nationally known water bottling company. the water bottling company’s specifications state that the standard deviation of the amount of water is equal to 0.02 gallon. a random sample of 50 bottles is selected, and the sample mean amount of water per 1-gallon bottle is 0.995 gallon a. construct a 99% confidence interval estimate for the popula-tion mean amount of water included in a 1-gallon bottle. b. on the basis of these results, do you think that the distributor has a right to complain to the water bottling company? why? c. must you assume that the population amount of water per bottle is normally distributed here? explain. d. construct a 95% confidence interval estimate. how does this change your answer to (b)?