What is the answer to 2 1/2 times 4/7? I was wondering because I am horrible at maths and I would like some help. Thanks :)

On a piece of paper graph f(x)=5•(0.4)^x

In two or more complete sentences, determine the appropriate model for the given data and explain how you made your decision. (1,-1), (2,0.5), (5,1.5), (8,2)

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.