Answer:

And the best option would be:

Step-by-step explanation:
We assume that the distribution for the random variable is:

For this case we want to calculate the following probability:

And we can use the normal standard distribution or excel and we got:

And the best option would be:

Answer:
x = -5
Step-by-step explanation:
Since these two triangles are similar, the ratio between the corresponding lengths of each triangle will be the same.
This means the ratio between one side of each triangle (e.g. AD and DC) will be the same as the ratio between a different side of each triangle (e.g. BE and BC).
So, to create an equation for the sides which contain the unknown 'x', we must first find the ratio between the two sides by using a different set of sides.
On the right side we are given 9 for AD, and 18 for DC.
9/18 = 0.5
This means that the extra length of the larger triangle from the smaller one (AD) is half the length of the smaller triangle (DC). We can use this to make an equation for x:
If AD/DC = 0.5, then BE/EC will also = 0.5
BE = x+23
EC = x+41
Therefore:

Now we can solve by multiplying both sides by x+41 to eliminate the fraction:

Now we multiply out the brackets and move the terms to different sides:



And if we substitute the -5 into the equations:
-5+23 = 18
-5 + 41 = 36
We will see that -5 does indeed give us the same ratio between the lengths:
18/36 = 0.5
Hope this helped!
Answer:
-5n + 8
Step-by-step explanation:
<u>1. What is the difference?</u>
The sequence goes down by 5. This means that the formula will have -5n in it.
<u>2. Work out the term before the first term.</u>
The first term is 3, and we know that the sequence goes up by 5. So, to get the term before 3 we would add 5.
3 + 5 = 8 Remember, this is positive 8. (+8)
<u>3. Put that term at the end of the equation. </u>
We have -5n already and we just worked out the term before the first one which is positive 8 - so put that at the end of the equation.
-5n + 8 This is our answer!
Just to prove it works:
<em>Substitute: n = term</em>
Lets see if we can get the 3rd term which is -7. (n = 3)
-5(3) + 8
-15 + 8 = -7
See, it works!