The function above models the height, y, in feet of a stone t seconds after it is dropped from the edge of a vertical cliff. How long will it take the stone to hit the ground? Round to the nearest hundredth of a second

3.94 seconds

Step-by-step explanation:

h = - 16t² + 248

If stone is dropped, then h = 0

- 16t² + 248 = 0

t² =

t = ±

t < 0 is a solution of equation, but not a solution of the task

t = ≈ 3.94 seconds

P(200 ≤ X ≤ 500) = 0.9973

Step-by-step explanation:

Let assume that the question intends us to find what percentage of students scored between 500 and 200 on this test.

Given that:

We need to first compute the Z test statistics

Thus;