Scores on a test have a mean of 70.9 and 7 percent of the scores are above 87. The scores have a distribution that is approximately normal. Find the standard deviation

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

Monica build a remote control toy airplane for science project to test the plane she launched it from the top of a building the plane travel a horizontal distance of 50 feet before landing on the ground a quadratic function which models the height of the plane in feet relative to the ground at a horizontal distance of x feet from the building is shown

The sum of 5consecutive even numbers is 100. what is the first number in this sequence?