Seven of the 28 dogs at the shelter are purebred. What percent of the dogs are purebred? (Please help I have been stuck on this question for an hour) The question is set up btw-

Marcus needs to rewrite f(x) = x2 + 6x + 4 in vertex form.

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

The weight of full–grown tomatoes at a farm is modeled by a normal distribution with a standard deviation of 18.4 grams. the 95 percent confidence interval for the mean weight of the tomatoes is calculated using a sample of 100 tomatoes. what is the margin of error (half the width of the confidence interval)?