Answer:
In February, 423 daytime minutes is used
Step-by-step explanation:
Let the base plan charges be x
And cost per daytime minute be y
In December,
x + 510y = 92.25------------------(1)
In January,
x + 397y = 77.56---------------------(2)
Subtracting eq(2) from eq(1)
x + 510y = 92.25
x + 397y = 77.56
-------------------------------
0 + 113y = 14.69
-------------------------------
y = \frac{14.69}{113}
y = 0.13----------------------------------(3)
Substituting (3) in (1)
x + 510(0.13) = 92.25
x + 66.3 = 92.25
x = 92.25 - 66.3
x = 25.95
So In February
base plan + (daytime minute)(cost per daytime minute) = 80.9
25.95 + (daytime minute)(0.13) = 80.9
(daytime minute)(0.13) = 80.9 - 25.95
(daytime minute)(0.13) = 54.95
(daytime minute) =
daytime minutes = 422.69
daytime minute 
Differences between two samples are least likely to be statistically significant if<span>the samples are small and the standard deviations of the samples are large</span>
Answer:
a=7
Step-by-step explanation:
The image is rendered and attached below.
Triangle WXY is an Isosceles right triangle, since WX=XY.
First, we determine the length of WY using Pythagoras Theorem.

Since triangle WXY is Isosceles, 

Therefore:
Triangle WYZ is a right triangle with WZ as the hypothenuse.
Applying Pythagoras Theorem

Answer: "Use the straightedge to draw a line through points X and Y." is the right answer.
Step-by-step explanation:
To perpendicular bisector of line segment AB. There are following steps:
1) Draw arcs from points A and B on the both sides of AB.
2) Name the intersection points as X and Y.
3) Use the straightedge to draw a line through points X and Y.
4) Name the point as O
hence we have construct perpendicular bisector XY of AB which bisects at O.