Xian plans to run 20 laps around a track. each lap is 400 yards. so far xian has to run 1680 yards around the track. what percentage of the run has xian completed.

For one history test, keith had to answer 40 questions. of these 40 questions, keith answered 28 of them correctly. what percent did keith get on his history test? round your answer to the nearest tenth if necessary

If a baby uses 15 diapers in 2 days, how many diapers will the baby use in a year?

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