$\bar{x}=\frac{4+6+8+9+9}{5}=\frac{36}{5}=7.2$ so the mean is 7.2. To find the population variance (which is almost exactly the same as the sample variance except for a small difference in the denominators of the formula) we have to take each number minus the mean, and then square the difference. Add together all these squared numbers and then divide by the number of numbers. Like this:

$(4-7.2)^2=10.24\\(6-7.2)^2=1.44\\(8-7.2)^2=.64\\(9-7.2)^2=3.24\\(9-7.2)^2=3.24$

Add together those numbers and divide them by 5:

$\sigma=\frac{10.24+1.44+.64+3.24+3.24}{5}=\frac{18.8}{5}=3.76$

5 0

2 years ago

I need help answering this question..

Irina-Kira [14]

Answer:

$x=3$

Step-by-step explanation:

Given: $15=7x-6$

To solve this equation, we need to isolate $x$ on one side of the equation algebraically. I see that we have like terms, but they are on opposite sides of the equal sign. Let's add $6$ to both sides.

$21=7x$

To isolate x, divide both sides by 7.

$x=3$

7 0

2 years ago

Helppp Plssss Asap!! Thanks​

Helppp Plssss Asap!! Thanks