1. The La Leche Society has released an educational video on the benefits of breast feeding. Prior to the release of the videos, it was known that 75% of new moms breast-feed exclusively for the first six weeks of their child's life. The CEO wants to know if the videos are increasing this proportion. A random sample of 400 new moms was obtained and 320 breast-fed their new babies exclusively for the first six weeks. At the 5% significance level, what conclusion can be reached?

Public Agenda conducted a survey of 1379 parents and 1342 students in grades 6-12 regarding the importance of science and mathematics for success in life after school. 50% of the students thought these skills were essential and 62% of the parents thought these subjects were crucial for success. The two random samples were selected independently of each other. Is there enough evidence to conclude that the proportion of parents who feel science and math are important for success is higher than the proportion of students who feel the same way? Conduct your test with a level of significance of 0.05.

The owner of Maumee Ford-Volvo wants to study the relationship between the age of a car and its selling price. Listed below is a random sample of 12 used cars sold at the dealership during the last year.  Car Age (years) Selling Price ($000) 1 11 12.1 2 8 10.5 3 14 5.7 4 17 4.9 5 9 5.0 6 8 13.4 7 10 10.5 8 14 9.0 9 13 9.0 10 17 4.5 11 6 12.5 12 6 11.5   Click here for the Excel Data Filea. Determine the regression equation. (Negative amounts should be indicated by a minus sign. Round your answers to 3 decimal places.) a= b=   Estimate the selling price of an 7-year-old car (in $000). (Round your answer to 3 decimal places.) Interpret the regression equation (in dollars). (Round your answer to the nearest dollar amount.)

Acne is a common skin disease that affects most adolescents and can continue into adulthood. A study compared the effectiveness of three acne treatments and a placebo, all in gel form, applied twice daily for 12 weeks. The study's 517 teenage volunteers were randomly assigned to one of the four treatments. Success was assessed as clear or almost clear skin at the end of the 12 week period. The results of the study can be seen in the table below. Using the appropriate statistical test, determine if there is significant evidence that the four treatments perform differently. If so, how do they compare.