The mean is the same thing as the average. To find the average, add all the numbers up (aka find the sum of the numbers) and divide by how many numbers there is:
So the sum of your numbers is: -6 + 2 + 5 + -7 + -11 + -6 = -23. And there are 6 numbers total.
That means average =
≈ -3.8
Your final answer is -3.8
Because there was a pay rise, we can write the equation as x+0.04x = 24.492 and solve for x.
x+0.04x = 24.492
1.04x = 24.492
x=23.55
His original pay was £23.55
<span>Given the diagram, where AB and EF are horizontal lines and CB is a vertical line segment.
Given that FB : FC = 4 : 3,
From the diagram, the coordinate of A is (-10, -8) and the coordinate of C is (-3. -1).
We can also see that the coordinate of B is (-3, -8) (since CB is a vertical line means that B is the same x-value as C and AB is a horizontal line means that B is the same y-value as A)
Recall that the coordinate of a point dividing a line segment in the ratio m:n is given by (x1 + m/(m+n) (x2 - x1), y1 + m/(m+n) (y2 - y1))
Thus, since FB : FC = 4 : 3, this means that point F divides the line segment BC in the ratio 4 : 3.
Thus, the coordinate of F is given by (-3 + 4/(4+3) (-3 - (-3)), -8 + 4/(4+3) (-1 - (-8))) = (-3 + 4/7 (0), -8 + 4/7 (7)) = (-3, -4).
Also, given that FB : FC = 4 : 3, this means that point D divides the line segment AC in the ratio 4 : 3.
Thus, the coordinate of D is given by (-10 + 4/(4+3) (-3 - (-10)), -8 + 4/(4+3) (-1 - (-8))) = (-10 + 4/7 (7), -8 + 4/7 (7)) = (-6, -4).
Therefore, the coordinates of point D is (-6, -4).</span>
It's difficult to make out what the force and displacement vectors are supposed to be, so I'll generalize.
Let <em>θ</em> be the angle between the force vector <em>F</em> and the displacement vector <em>r</em>. The work <em>W</em> done by <em>F</em> in the direction of <em>r</em> is
<em>W</em> = <em>F</em> • <em>r</em> cos(<em>θ</em>)
The cosine of the angle between the vectors can be obtained from the dot product identity,
<em>a</em> • <em>b</em> = ||<em>a</em>|| ||<em>b</em>|| cos(<em>θ</em>) ==> cos(<em>θ</em>) = (<em>a</em> • <em>b</em>) / (||<em>a</em>|| ||<em>b</em>||)
so that
<em>W</em> = (<em>F</em> • <em>r</em>)² / (||<em>F</em>|| ||<em>r</em>||)
For instance, if <em>F</em> = 3<em>i</em> + <em>j</em> + <em>k</em> and <em>r</em> = 7<em>i</em> - 7<em>j</em> - <em>k</em> (which is my closest guess to the given vectors' components), then the work done by <em>F</em> along <em>r</em> is
<em>W</em> = ((3<em>i</em> + <em>j</em> + <em>k</em>) • (7<em>i</em> - 7<em>j</em> - <em>k</em>))² / (√(3² + 1² + 1²) √(7² + (-7)² + (-1)²))
==> <em>W</em> ≈ 5.12 J
(assuming <em>F</em> and <em>r</em> are measured in Newtons (N) and meters (m), respectively).
