Answer:
x = 2 ±i
Step-by-step explanation:
x^2 = 4x-5
Subtract 4x from each side
x^2 - 4x = 4x-5 -4x
x^2 - 4x= -5
Complete the square
Take the coefficient of the x term, divide by 2 and square it
-4/2 =2 2^2 =4
Add 4 to each side
x^2 -4x+4 = -5 +4
The left side is (x-coefficient of the x term/2)^2
(x-2)^2 = -1
Take the square root of each side
sqrt((x-2)^2) = sqrt(-1)
x-2 = ±i
Add 2 to each side
x-2+2 = 2 ±i
x = 2 ±i
Answer:
And we can find this probability using the complement rule and the normal standard table or excel:
The firgure attached illustrate the problem
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the retirement savings of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule and the normal standard table or excel:
The firgure attached illustrate the problem
Answer:
-11 im pretty sure
Step-by-step explanation:
Answer:
Step-by-step explanation:
Simplify the radical by breaking the radicand up into a product of known factors.
Like this :