Answer:

And we can solve this using the following z score formula:

And if we use this formula we got:

So we can find this probability equivalently like this:

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:

And we can solve this using the following z score formula:

And if we use this formula we got:

So we can find this probability equivalently like this:

Answer:
y = 89 x = 123
Step-by-step explanation:
since they're both in standard form, its easier to do the process of elimination
x - y = 34
-x -y -212
------------------
-2y = -178
y = 89
now plug in y to any one of those two equations
x - y = 34
x - 89 = 34
x = 123
<em>to check:</em>
<em>x</em><em> </em><em>+</em><em> </em><em>y</em><em> </em><em>=</em><em> </em><em>2</em><em>1</em><em>2</em>
<em>1</em><em>2</em><em>3</em><em> </em><em>+</em><em> </em><em>8</em><em>9</em><em> </em><em>=</em><em> </em><em>2</em><em>1</em><em>2</em>
<em>2</em><em>1</em><em>2</em><em> </em><em>=</em><em> </em><em>2</em><em>1</em><em>2</em>
I... don’t know? How many hours is he working a year? How many days is he working?
Answer:D
Step-by-step explanation: