Answer:
The mean is 
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the mean of this normal distribution if the probability of scoring above x = 209 is 0.0228?
This means that when X = 209, Z has a pvalue of 1-0.0228 = 0.9772. So when X = 209, Z = 2.





The mean is 
Answer:
The scale factor is 0.5
Step-by-step explanation:
Divide.
2/1=2
4/2=2
4/2=2
8/4=2
2/1=2
5/1.25=2
Now then, since this is a shrinking factor, divide 1 by the common outcome from the last section (2) to get 0.5
To do this problem, you will need to know the side lengths of the triangle. If you have those, just plug them in for a, b, and c and evaluate the square root.
Here is an example. If the sides are 3, 4, 5.
It would be:

The 6 is in the formula because it is the semi-perimeter (half).
Answer:
9. x=-6, y=0
10. x=-9, y=-10
11. x=3, y=-1
Step-by-step explanation:

Multiply the first equation by 2.

Add the equations.


We figured out x now we have to figure out y. To figure out y plug in x into any equation.




Your answer is x = -6 and y = 0 for number nine.

Change the signs of the second equation becuase 3y and 3y are both positive. We need one of them to be negative.

Add them.


Now we have to figure out y.




x=-9 and y=-10 is your answer to number ten.








x=3 and y=-1 is the answer to number eleven. I hope this helps! Let me know if I got anything wrong.