What is the surface area of a sphere with radius 4

Describe all the numbers that when rounded to the nearest thousand are 645,000

An ulcer medication has 300 milligrams in 2 tablets. how many milligrams are in 3 tablets?

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