8. A new program to help reduce childhood obesity was recently studied in Granollers, Spain. The city of Granollers has 16 primary schools that were randomly divided into two groups of 8 schools each....

Extracted text: 8. A new program to help reduce childhood obesity was recently studied in Granollers, Spain. The city of Granollers has 16 primary schools that were randomly divided into two groups of 8 schools each. In one group of schools, new lesson plans were used for three hours per week that included activities focusing on healthy eating and encouraging physical activity. The families of the children at those schools were given healthy recipes and information about local parks for outdoor activities. In the other 8 schools instruction continued as normal. After two years of the program, it turned out that the average body mass index of the children at the schools with the new program was significantly lower than the average for the children at the other schools and that the amount of fresh fruit and fish in their diet and the amount of after school exercise increased significantly. a. Is this an experiment or an observational study? Explain b. The subjects and school administrators all knew which of the two comparison groups they belonged to. Describe how that might affect the results of the study c. The word "significantly in the last sentence of the paragraph indicates that the new programs are likely to be effective in other cities. B. that the differences between the children at the two groups of schools were very large. C. that the differences between the children at the two groups of schools could not be easily explained by random chance D. that the new lesson plans must have caused the differences seen.