Answer: 47 degrees
Step-by-step explanation:
7x-9=4x+15 because of the vertical angle rule
7x-9=4x+15
3x=24
x= 8
So the angle 7(8)-9 = 47°
Answer:
I don't know how to do it...
Answer:
39
Step-by-step explanation:
63/4 + 42/4 + 51/4
= 63/4 + 21/2 + 51/4
= 63/4 + 93/4
=39
With the given equation, you have to determine the defined range.
Simplify the equation using cross-multiply.
W^2=4(2w-3)
Move the expression to the left side and change its sign.
w^2-4(2w-3)=0
Next, Distribute "-4" through the parenthesis
w^2-8w+12=0
Solve by using the quadratic equation. "x= +- Sqr (b)^2-4(a)(c) / 2(a)"
-(-8)+-Sqr (-8)^2-4(1)(12) / 2(1)
solve the equation
w=8 +- Sqr of 16
You got to separate the equation into two other equations and simplify it.
w= 8+4/2 +6
w=8-4/2=2
The correct answer is 6 and 2.
Answer:
![P(\bar X >1650)=P(Z>\frac{1650-1637.52}{\frac{623.16}{\sqrt{400}}}=0.401)](https://tex.z-dn.net/?f=P%28%5Cbar%20X%20%3E1650%29%3DP%28Z%3E%5Cfrac%7B1650-1637.52%7D%7B%5Cfrac%7B623.16%7D%7B%5Csqrt%7B400%7D%7D%7D%3D0.401%29)
And we can use the complement rule and we got:
![P(Z>0.401) =1-P(Z](https://tex.z-dn.net/?f=P%28Z%3E0.401%29%20%3D1-P%28Z%3C0.401%29%20%3D%201-0.656%3D%200.344)
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 bank account balances of a population, and for this case we know the distribution for X is given by:
Where
and
Since the distribution of X is normal then the distribution for the sample mean
is given by:
And we can use the z score formula given by:
![z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}](https://tex.z-dn.net/?f=%20z%20%3D%20%5Cfrac%7B%5Cbar%20X%20-%5Cmu%7D%7B%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%7D)
And using this formula we got:
![P(\bar X >1650)=P(Z>\frac{1650-1637.52}{\frac{623.16}{\sqrt{400}}}=0.401)](https://tex.z-dn.net/?f=P%28%5Cbar%20X%20%3E1650%29%3DP%28Z%3E%5Cfrac%7B1650-1637.52%7D%7B%5Cfrac%7B623.16%7D%7B%5Csqrt%7B400%7D%7D%7D%3D0.401%29)
And we can use the complement rule and we got:
![P(Z>0.401) =1-P(Z](https://tex.z-dn.net/?f=P%28Z%3E0.401%29%20%3D1-P%28Z%3C0.401%29%20%3D%201-0.656%3D%200.344)