Answer: The mean temperature for the first eight days is 6.5 degrees
Step-by-step explanation: The most important piece of clue has been given which is the mean (average) for the observed data set, which is 7 days.
Note that the formula for the mean of a data set is derived as;
Mean = ∑x / f
Where ∑x is the summation of all observed data set and f is the number of data observed, that is 7. The formula now becomes;
6 = ∑x / 7
By cross multiplication, we now have,
6 * 7 = ∑x
42 = ∑x
This means the addition of all temperature observed on the first 7 days is 42. The temperature on the eighth day is now given as 10 degrees, this means the summation of all observed data for the first eight days would become 42 + 10 which equals 52. Therefore when calculating the mean for the first eight days, ∑x is now 52. The formula for the first eight days therefore is derived as follows;
Mean = ∑x / 8
Mean = 52 / 8
Mean = 6.5
The calculations therefore show that the mean temperature for the first eight days in January is 6.5 degrees
<em>Coplanar</em> means "lying on the same plane," while <em>colinear </em>means "lying on the same line." In this problem, all four points A, B, C, and D are coplanar - they all lie on the plane 
- so we just need to find the points that lie on the same line. Though points C and B <em>would </em>be colinear if there was a line drawn between them, there's no such line in this problem, so we can rule that out. We notice one line drawn on the plane, and points A, C, and D lying on it, so we can say that points A, C, and D are both coplanar and colinear.
The triangle was only rotated. The size did not change, so the corresponding angles would remain identical.
Because C is 28 degrees C' would also be 28 degrees.
Let's simplify step-by-step.
2(x+7)+3(x+1)
Distribute:
=(2)(x)+(2)(7)+(3)(x)+(3)(1)
=2x+14+3x+3
Combine Like Terms:
=2x+14+3x+3
=(2x+3x)+(14+3)
=5x+17
your answer is 5x+17
