Many medical professionals believe that smoking increases the risk of heart disease and cancer. A medical researcher would like to conduct a survey to determine the monthly consumption of cigarettes by a typical consumer (i.e., to estimate the average monthly consumption of smokers). Her research budget is $2,000 and the cost of collecting an observation is $10. Her target is to find a 90% confidence interval estimate with a range of 3 cigarettes. If the population standard deviation is 12 cigarettes, is her budget sufficient for conducting such a survey to achieve her target? Explain.

You are a researcher studying a certain species of fish in a local lake.  You gather a random sample of 19 fish of this species and record the lengths (in centimeters) of the fish. The data is displayed in the table below.  Estimate the mean length of all fish of this type in the lake.  Use a 99% confidence level. 9.1 9 8.6 5.8 9.8 7.4 9.1 9.5 8.2 8.9 9.3 7.8 9 9.6 10.4 13.6 7.2 10.1 8.9   a)  Find the confidence interval:  b) What is the margin of error of your interval?  c) Interpret your 99% confidence interval in context

The Statistics Games are played by a large number of teams across the county. Teams raise money to cover expenses incurred by participating. You want to estimate the mean amount of money raised by teams. You take a random sample of 36 teams and find a mean of $375, with a standard deviation of $32. What critical value should you use for a 95% confidence interval?

You hypothesize that people in stats classes are happier than people in all other classes. You compare happiness scores in three of your classes: Statistics, Developmental Psychology, and Social Psychology. In Statistics there are 15 students and the mean happiness rating is  23.1 with a standard deviation of 9.78. In Developmental Psychology there are 15 students and the mean happiness rating is 24.4 with a standard deviation of 2.92. In Social Psychology there are 15 students with a mean rating of 17.7 and  standard deviation of 8.46. The sum of squares between groups is equal to 384. The sum of squares within groups is equal to 2461.  Use the One-Way ANOVA calculation table to help calculate. What is the degrees of freedom between samples?