Answer:
The fraction of females on the maths course at university is 3/4
Step-by-step explanation:
Males = x
Females = 3x
Males + Females = x + 3x = 4x
The fraction of the course that are females
Females fraction = Females/Males + Females
Females fraction = 3x/4x= 3/4
which means that for every 4 people 3 are females and 1 male
Answer fast? What?
x + 2y = 17...Equation A
8x + 3y = 45...Equation B
Solve A for x.
x = 17 - 2y
Plug this into B to solve for y.
8(17 - 2y) + 3y = 45
136 - 16y + 3y = 45
136 - 13y = 45
-13y = 45 - 136
-13y = -91
y = -91/-13
y = 91/13
y = 7
To find y, plug x = 7 into either equation to find x.
I will use Equation A.
x + 2y = 17
x + 2(7) = 17
x + 14 = 17
x = 17 - 14
x = 3
Answer: x = 3, y = 7
Answer:
all i know is that the perimeter is 24
Step-by-step explanation:
i also believe that the Coordinate on the top left is (-4,4) and the one below is (0,4)
Answer:
The mean number of cars recovered after being stolen is 267 and the standard deviation is 5.42.
Step-by-step explanation:
For each stolen car, there are only two possible outcomes. Either it is recovered, or it is not. The probability of a stolen car being recovered is independent of other stolen cars. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
![E(X) = np](https://tex.z-dn.net/?f=E%28X%29%20%3D%20np)
The standard deviation of the binomial distribution is:
![\sqrt{V(X)} = \sqrt{np(1-p)}](https://tex.z-dn.net/?f=%5Csqrt%7BV%28X%29%7D%20%3D%20%5Csqrt%7Bnp%281-p%29%7D)
In this problem, we have that:
![n = 300, p = 0.89](https://tex.z-dn.net/?f=n%20%3D%20300%2C%20p%20%3D%200.89)
So
![E(X) = np = 300*0.89 = 267](https://tex.z-dn.net/?f=E%28X%29%20%3D%20np%20%3D%20300%2A0.89%20%3D%20267)
![\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{300*0.89*0.11} = 5.42](https://tex.z-dn.net/?f=%5Csqrt%7BV%28X%29%7D%20%3D%20%5Csqrt%7Bnp%281-p%29%7D%20%3D%20%5Csqrt%7B300%2A0.89%2A0.11%7D%20%3D%205.42)
The mean number of cars recovered after being stolen is 267 and the standard deviation is 5.42.