The actual or true value of the diameter of a shaft is 18.276 in. The shaft is measured at 18.540 in. What is the percent error to the nearest tenth of a percent?

Joseph haydn pet store offers wide variety of leashes for dogs. the store purchases one popular type of leash from its manufacturer for $4.38 each. joseph haydn pets marks up leashes at a rate of 238% of cost. what is the retail price of the popular leash?

I'm confused on this could anyone me and show me what i need to do to solve it.

If f(x)=x+7 and g(x)=1/x what is (fog)(x)