Be sure to include the "=" sign: <span>f(x) = 2^x -7
To find the x-intercepts, set f(x) = 0 and solve for x: 2^x - 7 = 0,
or
2^x = 7
Take the common log of both sides: x log 2 = log 7
log 7
Solve for x: x = --------- = 2.81 (approx)
log 2
</span>
The x is going to be a negative number to get the 3. so start off minus 5 from plus 5 and minus five from the other side too. the positive 5 and the negative cancel out and then take it fromt here with three and the negative 5.
Answer:
-2
Step-by-step explanation:
because the slope is 2, a perpendicular line must be the inverse
the equation for y1 is y=2x+1
y2= -2y+1
Answer:
a) 
And replacing we got:

b) ![E(80Y^2) =80[ 0^2*0.45 +1^2*0.2 +2^2*0.3 +3^2*0.05]= 148](https://tex.z-dn.net/?f=%20E%2880Y%5E2%29%20%3D80%5B%200%5E2%2A0.45%20%2B1%5E2%2A0.2%20%2B2%5E2%2A0.3%20%2B3%5E2%2A0.05%5D%3D%20148)
Step-by-step explanation:
Previous concepts
In statistics and probability analysis, the expected value "is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values".
The variance of a random variable Var(X) is the expected value of the squared deviation from the mean of X, E(X).
And the standard deviation of a random variable X is just the square root of the variance.
Solution to the problem
Part a
We have the following distribution function:
Y 0 1 2 3
P(Y) 0.45 0.2 0.3 0.05
And we can calculate the expected value with the following formula:

And replacing we got:

Part b
For this case the new expected value would be given by:

And replacing we got
![E(80Y^2) =80[ 0^2*0.45 +1^2*0.2 +2^2*0.3 +3^2*0.05]= 148](https://tex.z-dn.net/?f=%20E%2880Y%5E2%29%20%3D80%5B%200%5E2%2A0.45%20%2B1%5E2%2A0.2%20%2B2%5E2%2A0.3%20%2B3%5E2%2A0.05%5D%3D%20148)
The answer would be 25% or 1/4 if you wanted it in fraction form.