I'm not sure does anyone else know the answer?
Answer:


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 grade points avergae of a population, and for this case we know the following properties
Where
and
The empirical rule, also referred to as the three-sigma rule or 68-95-99.7 rule, is a statistical rule which states that for a normal distribution, almost all data falls within three standard deviations (denoted by σ) of the mean (denoted by µ). Broken down, the empirical rule shows that 68% falls within the first standard deviation (µ ± σ), 95% within the first two standard deviations (µ ± 2σ), and 99.7% within the first three standard deviations (µ ± 3σ).
So we can find the z score for the value of X=3.44 in order to see how many deviations above or belowe we are from the mean like this:

So the value of 3.44 is 2 deviations above from the mean, so then we know that the percentage between two deviations from the mean is 95% and on each tail we need to have (100-95)/2 = 2.5% , because the distribution is symmetrical, so based on this we can conclude that:

<u>Answer:</u>
Perimeter = 20 units
x = 120°
<u>Step-by-step explanation:</u>
We are given a triangle ABC with known side lengths for all three sides and an inscribed circle.
We are to find the perimeter of triangle ABC and the value of x.
Perimeter of triangle ABC = 2 + 2 + 5 + 5 + 3 + 3 = 20 units
The kite shape at the end is a quadrilateral which has a sum of angles of 360 degrees.
Two out of four angles are right angles and one is 60 so we can find the value of x.
x = 360 - (90 + 90 + 60) = 120°
Answer:
B.) 
Step-by-step explanation:
Answer:
<em>Martin saved $75 on the television because of the sale</em>
Step-by-step explanation:
<u>Equations</u>
Let's call x=the original price of the television (before discount).
The television had been on sale for 25% off, this means the discount was:
25% of x =
= 0.25x
The sale price was the original price minus the discount:
x - 0.25x = 0.75x
This is what Martin paid, thus:
0.75x = 225
Dividing by 0.75:
x = 225 / 0.75
x = $300
The original price of the television was $300, and the discount was:
0.25*$300 = $75
Martin saved $75 on the television because of the sale