Answer:
Variance = 25
Step-by-step explanation:
<em>Standard deviation is the under root of variance.</em>
<em>Variance is the square of standard deviation.</em>
<u>Data:</u>
Mean = 70
Variance = ?
Standard deviation = √variance = 5
Variance = 5²
Variance = 25.
Therefore, the variance is 25.
W 7ayat Omi 7atbha 12 it will be 12
Answer:
Step-by-step explanation:
Let's call lifeguarding L and car washing W. In order to write a system, we need to first separate the NUMBER of hours worked from the MONEY earned, because they are very different things.
If she works 10 hours, that is the number of hours worked between both jobs. Therefore, the equation for the NUMBER of hours worked is
L + W = 10.
If she earns $13 an hour lifeguarding, the expression for that is 13L; if she earns $12 an hour car washing, the expression for that is 12W. The MONEY she earned together by doing both those jobs is
13L + 12W = 124
There you go!
The answer would be B. 3x^2 + 12x
