The liberty high football players don't like the bellevue high football players very much. but when they had to work together on a project to raise money for autism, they found they liked each other and worked together well. this is an example of:

The kamp family has twins, rob and rachel. both rob and rachel graduated from college 2 years ago, and each is now earning $50,000 per year. rachel works in the retail industry, where the mean salary for executives with less than 5 years' experience is $35,000 with a standard deviation of $8,000. rob is an engineer. the mean salary for engineers with less than 5 years' experience is $60,000 with a standard deviation of $5,000.