Answer:


Step-by-step explanation:
For this case we have the following data given:
2.3 3.1 2.8
1.7 0.9 4.0
2.1 1.2 3.6
0.2 2.4 3.2
Since the data are assumedn normally distributed we can find the standard deviation with the following formula:

And we need to find the mean first with the following formula:

And replacing we got:

And then we can calculate the deviation and we got:

I got letter A when I tried it
Answer:
5.15
Step-by-step explanation:
5.15 = 3a + 2.15
5.15 - 2.15 = 3a
3.15 = 3a
a = 0.05
I hope this helps you :)
If the line segment is perpendicular to a line with the slope of -4, that means the line segment has a slope of 1/4.
First let's make an equation for the line segment using the slope of 1/4 and the point at (2,6) to find the final piece, the y-intercept
y = mx + b
6 = 1/4(2) + b
6 = 2/4 + b
24/4 = 2/4 + b
22/4 = b
y = 1/4 x + 22/4
6 = 1/4(2) + 22/4
6 = 2/4 + 22/4
6 = 24/4
6 = 6 <-- proves that this equation is correct
Now you may plug in the x to find y. ( 8 , y )
y = 1/4(8) + 22/4
y = 8/4 + 22/4
y = 30/4 = 15/2 = 7.5
Answer: Choice A. 
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Work Shown:
