Answer:
5500..?
Step-by-step explanation:
Answer:
Mean = 1.42
Variance = 0.58
Step-by-step explanation:
Given: X denote the number of luxury cars sold in a given day, and Y denote the number of extended warranties sold.
Also, joint probability function of X and Y are given.
To find:
mean and variance of X
Solution:
From the given joint probability function of X and Y,
Mean of X:
Variance of X:
![var(X)=E\left [ X^2 \right ]-\left ( E\left [ X \right ] \right )^2\\=\frac{31}{12}-\left ( \frac{17}{12} \right )^2\\=\frac{31}{12}-\frac{289}{144}\\=\frac{372-289}{144}\\=\frac{83}{144}\\=0.58](https://tex.z-dn.net/?f=var%28X%29%3DE%5Cleft%20%5B%20X%5E2%20%5Cright%20%5D-%5Cleft%20%28%20E%5Cleft%20%5B%20X%20%5Cright%20%5D%20%5Cright%20%29%5E2%5C%5C%3D%5Cfrac%7B31%7D%7B12%7D-%5Cleft%20%28%20%5Cfrac%7B17%7D%7B12%7D%20%5Cright%20%29%5E2%5C%5C%3D%5Cfrac%7B31%7D%7B12%7D-%5Cfrac%7B289%7D%7B144%7D%5C%5C%3D%5Cfrac%7B372-289%7D%7B144%7D%5C%5C%3D%5Cfrac%7B83%7D%7B144%7D%5C%5C%3D0.58)
X = rate of mechanic who worked 5 hours
y = rate of mechanic who worked 15 hours
x + y = 200
5x + 15y = 1950
you find the first variable in one of the equations, then subsitute the result into the other equation. your answer would be:
the mechanic who worked for 5 hours charged $105 per hour, the one who worked 15 hours charged $95 per hour.
hope this helps :)
Answer:
Step-by-step explanation:
We will make a table and fill it in according to the information provided. What this question is asking us to find, in the end, is how long did it take the cars to travel the same distance. In other words, how long, t, til car 1's distance = car 2's distance. The table looks like this:
d = r * t
car1
car2
We can fill in the rates right away:
d = r * t
car1 40
car2 60
Now it tells us that car 2 leaves 3 hours after car 1, so logically that means that car 1 has been driving 3 hours longer than car 2:
d = r * t
car1 40 t + 3
car2 60 t
Because distance = rate * time, the distances fill in like this:
d = r * t
car1 40(t + 3) = 40 t+3
car2 60t = 60 t
Going back to the interpretation of the original question, I am looking to solve for t when the distance of car 1 = the distance of car 2. Therefore,
40(t+3) = 60t and
40t + 120 = 60t and
120 = 20t so
t = 6 hours.
Answer:
its 40%
Step-by-step explanation:
ok so its 0.4 and there's a 0 in it so you swop the number and then you get it and. I hope you enjoy.
