A carpenter used 24 boards each measuring 3 3/4in. long how many feet long is the porch the he built?

Find the value of x. round the length to the nearest tenth

List x1, x2, x3, x4 where xi is the left endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 4 and x = 6. a 4, 4.5, 5, 5.5 b 4.5, 5, 5.5, 6 c 4.25, 4.75, 5.25, 5.75 d 4, 4.2, 5.4, 6

What percent of 18 is 24? and plz explain thx.