Answer:
![P(\bar X](https://tex.z-dn.net/?f=%20P%28%5Cbar%20X%20%3C63%29%20)
And we can solve this using the following z score formula:
![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 if we use this formula we got:
![z = \frac{63-63.6}{\frac{2.5}{\sqrt{100}}}= -2.4](https://tex.z-dn.net/?f=%20z%20%3D%20%5Cfrac%7B63-63.6%7D%7B%5Cfrac%7B2.5%7D%7B%5Csqrt%7B100%7D%7D%7D%3D%20-2.4)
So we can find this probability equivalently like this:
![P( Z](https://tex.z-dn.net/?f=%20P%28%20Z%3C-2.4%29%20%3D%200.0082)
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 heights of a population, and for this case we know the distribution for X is given by:
Where
and
We select n =100. Since the distribution for X is normal then we know that the distribution for the sample mean
is given by:
We want this probability:
![P(\bar X](https://tex.z-dn.net/?f=%20P%28%5Cbar%20X%20%3C63%29%20)
And we can solve this using the following z score formula:
![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 if we use this formula we got:
![z = \frac{63-63.6}{\frac{2.5}{\sqrt{100}}}= -2.4](https://tex.z-dn.net/?f=%20z%20%3D%20%5Cfrac%7B63-63.6%7D%7B%5Cfrac%7B2.5%7D%7B%5Csqrt%7B100%7D%7D%7D%3D%20-2.4)
So we can find this probability equivalently like this:
![P( Z](https://tex.z-dn.net/?f=%20P%28%20Z%3C-2.4%29%20%3D%200.0082)
Answer:
The coordinates of A would be (-1, 2)
Step-by-step explanation:
In order to find this, use the mid-point formula.
(xA + xB)/2 = xM
In this, the xA is the x value of point A, xB is the x value of point B, and xM is the x value of M. Now we plug in the known information and solve for xA.
(xA + 5)/2 = 2
xA + 5 = 4
xA = -1
Now we can do the same using the midpoint formula and the y values.
(yA + yB)/2 = yM
(yA + 10)/2 = 6
yA + 10 = 12
yA = 2
This gives us the midpoint of (-1, 2)
0.4(420) = 4(420)/10
(0.4 is essentially 4/10)
1680/10 = 168
There are 168 sixth graders
Answer:
A, a= 87
Step-by-step explanation:
a+36=123
Step 1: Subtract 36 from both sides.
a+36−36=123−36
a=87
Hope this helps!