How many 3 digit numbers can you make using these numbers: 4,2,9 (numbers can be reapeated)

Will give brainliest if you answer question correct

Which math sentence can be used to determine if the triangle is a right triangle?

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed