Answer:
51/4
Step-by-step explanation:
To begin with you have to understand what is the distribution of the random variable. If X represents the point where the bus breaks down. That is correct.
X~ Uniform(0,100)
Then the probability mass function is given as follows.

Now, imagine that the D represents the distance from the break down point to the nearest station. Think about this, the first service station is 20 meters away from city A, and the second station is located 70 meters away from city A then the mid point between 20 and 70 is (70+20)/2 = 45 then we can represent D as follows

Now, as we said before X represents the random variable where the bus breaks down, then we form a new random variable
,
is a random variable as well, remember that there is a theorem that says that
![E[Y] = E[D(X)] = \int\limits_{-\infty}^{\infty} D(x) f(x) \,\, dx](https://tex.z-dn.net/?f=E%5BY%5D%20%3D%20E%5BD%28X%29%5D%20%3D%20%5Cint%5Climits_%7B-%5Cinfty%7D%5E%7B%5Cinfty%7D%20D%28x%29%20f%28x%29%20%5C%2C%5C%2C%20dx)
Where
is the probability mass function of X. Using the information of our problem
![E[Y] = \int\limits_{-\infty}^{\infty} D(x)f(x) dx \\= \frac{1}{100} \bigg[ \int\limits_{0}^{20} x dx +\int\limits_{20}^{45} (x-20) dx +\int\limits_{45}^{70} (70-x) dx +\int\limits_{70}^{100} (x-70) dx \bigg]\\= \frac{51}{4} = 12.75](https://tex.z-dn.net/?f=E%5BY%5D%20%3D%20%5Cint%5Climits_%7B-%5Cinfty%7D%5E%7B%5Cinfty%7D%20%20D%28x%29f%28x%29%20dx%20%5C%5C%3D%20%5Cfrac%7B1%7D%7B100%7D%20%5Cbigg%5B%20%5Cint%5Climits_%7B0%7D%5E%7B20%7D%20x%20dx%20%2B%5Cint%5Climits_%7B20%7D%5E%7B45%7D%20%28x-20%29%20dx%20%2B%5Cint%5Climits_%7B45%7D%5E%7B70%7D%20%2870-x%29%20dx%20%2B%5Cint%5Climits_%7B70%7D%5E%7B100%7D%20%28x-70%29%20dx%20%20%5Cbigg%5D%5C%5C%3D%20%5Cfrac%7B51%7D%7B4%7D%20%3D%2012.75)
Answer:
2.225 kg
Step-by-step explanation:
We know that the total weight the farmer sold was 8.9 kilograms.
- 3/4 of this weight is apples, and the rest is pears.
Therefore, to calculate the amount of kilograms of pears she sold at the farmer's market (which you can call x), you need to apply the following procedure.
Answer:
10. y=2x+1 y = -1/2x +1
11. y=-1/3x +6 y = 3x -4
12. y=-5x-18 y=1/5x + 14/5
Step-by-step explanation:
To write the equation of a line we must have a slope and a point. To find the slope, we use the slope from the equations for parallel lines and modify it for perpendicular lines.
10. Use the point-slope form to write the equation, then simplify and convert into the slope intercept form. The slope here is 2. The parallel slope is 2 and the perpendicular slope is the negative reciprocal or -1/2.
Parallel Perpendicular
(y-1)=2(x-0) (y-1)==-1/2(x-0)
y-1=2x y-1 = -1/2 x
y=2x+1 y = -1/2x +1
11. Use the point-slope form to write the equation, then simplify and convert into the slope intercept form. The slope here is -1/3. The parallel slope is -1/3 and the perpendicular slope is the negative reciprocal or 3.
Parallel Perpendicular
(y-5)=-1/3(x-3) (y-5)=3(x-3)
y-5=-1/3x+1 y-5 = 3x - 9
y=-1/3x +6 y = 3x -4
12. Use the point-slope form to write the equation, then simplify and convert into the slope intercept form. The slope here is -5. The parallel slope is -5 and the perpendicular slope is the negative reciprocal or 1/5.
Parallel Perpendicular
(y-2)=-5(x--4) (y-2)=1/5(x--4)
y-2=-5(x+4) y-2 = 1/5(x +4)
y-2=-5x -20 y-2 = 1/5x +4/5
y=-5x-18 y=1/5x + 14/5
Answer:
3/1 or 3
Step-by-step explanation:
It rises up three and to the side one