Answer:
The standard deviation is 2.6832815729997
Step-by-step explanation:
SD^2=(12-12)^2+...+(14-12)^2/10
SD^2=72/10
SD^2=7.2
SD=squeare root of 7.2
SD=2.6832815729997
Nancy is 9, tracy is 4, doug is 18, doug is the oldest.
Let y = x^2 - 1
x^2 = y + 1
x = sqrt(y + 1)
so f^-1(x) = sqrt (x + 1) (answer)
<h2>
a. What is your equation?</h2>
This is a problem of projectile motion. A projectile is an object you throw with an initial velocity and whose trajectory is determined by the effect of gravitational acceleration. The general equation in this case is described as:

Where:

So:

Finally, the equation is:

<h2>b. How long will it take the rocket to reach its maximum height?</h2>
The rocket will reach the maximum height at the vertex of the parabola described by the equation
. Therefore, our goal is to find
at this point. In math, a parabola is described by the quadratic function:

So the x-coordinate of the vertex can be calculated as:

From our equation:

So:

So the rocket will take its maximum value after 1.99 seconds.
<h2>
c. What is the maximum height the rocket will reach?</h2>
From the previous solution, we know that after 1.99 seconds, the rocket will reach its maximum, so it is obvious that the maximum height is given by
. Thus, we can find this as follows:

So the maximum height the rocket will reach is 66.68ft
<h2>
d. How long is the rocket in the air?</h2>
The rocket is in the air until it hits the ground. This can be found setting
, so:

We can't have negative value of time, so the only correct option is
and rounding to the nearest hundredth we have definitively:

The question is not clearly
So what is the question?