Z-score for 30 = (30 - 25) / 5.8 = 0.8621
z-score for 20 = (20 - 25) / 5.8 = -0.8621
:
Note find probabilities from z-tables
:
Probability ( 20 < X < 30 ) = 0.8051 - 0.1949 = 0.6102
Answer:


or

Step-by-step explanation:
We are going to see if the exponential curve is of the form:
, (
).
If you are given the
intercept, then
is easy to find.
It is just the
coordinate of the
intercept is your value for
.
(Why? The
intercept happens when
. Replacing
with 0 gives
. This says when
.)
So
.
So our function so far looks like this:

Now to find
we need another point. We have two more points. So we will find
using one of them and verify for our resulting equation works for the other.
Let's do this.
We are given
is a point on our curve.
So when
,
.


Divide both sides by 8:

Reduce the fraction:

So the equation if it works out for the other point given is:

Let's try it. So the last point given that we need to satisfy is
.
This says when
,
.
Let's replace
with 2 and see what we get for
:






So we are good. We have found an equation satisfying all 3 points given.
The equation is
.
Ok so I like to go in steps with these questions- first draw a picture and identify your variables.
W=width
L= 3w-1
Now we know that length times width gets us area so we plug in our variables into the area equation.
200 = w(3w-1)
When you foil that equation you end up with a quadratic : 3w^2-w-200 = 0
Either factor that or use the quadratic formula to get
w= 8.33 and w= -8
Since you can't have a negative dimension you need to use 8.33 and plug it back into your length equation.
Final answer:
w= 8.33ft
l= 23.99ft
*Now I simplified the decimals a little bit so you end up with 199.8ft^2 for the area so just add a few decimals on here and there*
They both have the same rate of change