Step-by-step explanation:
Points are (8,5) and (-12,-9)
The equation of a line passing through two points is given by :

or

But he writes the equation 7x – 10y = 3 which is not matching with the one we have calculated. It means that model calculated by Devon is not good.
Answer:
y = -1/2 x
Step-by-step explanation:
Follow the directions "Complete the steps to write the equation of direct variation. Start with the equation of direct variation y = kx. Substitute in the given values for x and y to get . Solve for k to get . Write the direct variation equation with the value found for k."
y = kx substitute y = -4 and x = 8.
-4 = k*8
-4/8 = k
-1/2 = k
So the equation is y = -1/2(x).
Question not correct, so i have attached the correct question.
Answer:
SE = 0.59
Step-by-step explanation:
The mean of the students height is;
x' = (53 + 52.5 + 54 + 51 + 50.5 + 49.5 + 48 + 53 + 52 + 50)/10
x' = 51.35
Now, deviation from the mean for each height;
53 - 51.35 = 1.65
52.5 - 51.35 = 1.15
54 - 51.35 = 2.65
51 - 51.35 = -0.35
50.5 - 51.35 = -0.85
49.5 - 51.35 = -1.85
48 - 51.35 = -3.35
53 - 51.35 = 1.65
52 - 51.35 = 0.65
50 - 51.35 = -1.35
Now, square of the deviations above;
1.65² = 2.7225
1.15² = 1.3225
2.65² = 7.0225
-0.35² = 0.1225
-0.85² = 0.7225
-1.85² = 3.4225
-3.35² = 11.2225
1.65² = 2.7225
0.65² = 0.4225
-1.35² = 1.8225
Sum of the squared deviations;
2.7225 + 1.3225 + 7.0225 + 0.1225 + 0.7225 + 3.4225 + 11.2225 + 2.7225 + 0.4225 + 1.8225 = 31.525
Let's divide the sum by the DF of n - 1 i.e 10 - 1 = 9.
Thus;
31.525/9 = 3.50278
Taking the square root of that gives us the standard deviation.
Thus;
s = √3.50278
s = 1.8716
Formula for standard error is;
SE = s/√n
SE = 1.8716/√10
SE = 0.59
Answer:
1) 120
2) E (Z) = 12 and Variance of Z = 90
a) 5 liters
Step-by-step explanation:
1. We can find this by suing combinations.
Here n= 10 and r= 3 so n C r
= 10 C 3= 120
2. E(X) = 8 and E(Y) = 3
Z = 2X - 3Y +5
E(Z ) = 2 E (X) - 3(E)(Y) +5 ( applying property for mean)
= 2(8) - 3(3)+ 5 = 16+5-9= 21-9= 12
V(X) = 9 and V(Y) = 6.
V(Z) = E(Z )²- V(X) *V(Y) (applying property for Variance for two variables )
= 144- 54= 90
3. 55 liters contain adulterated milk in 7: 4.
So it contains 4/ 11*55= 20 liters of water
But we want to make it a ratio of 7:6
the water will be 6/13 *55= 25.38 when rounded gives 25 liters of water
So 25- 20 = 5 liters must be added to make it a ratio of 7:6