Please help please help

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

Amodel rocket is launched from a roof into a large field. the path of the rocket can be modeled by the equation y = -0.04x^2 + 8.6x + 4.8, where x is the horizontal distance, in meters, from the starting point on the roof and y is the height, in meters, of the rocket above the ground. how far horizontally from its starting point will the rocket land? a. 0.56 m b. 215.56 m c. 431.11 m d. 215.74 m

Drag each number to the correct location on the statements. not all numbers will be used. consider the sequence below. -34, -21, -8, 5, complete the recursively defined function to describe this sequence