Answer:
0.1274
Step-by-step explanation:
Let X be the random variable that measures the number of children who get their own coat.
Then, the expected value of X is
E[X] = 1P(X=1) + 2P(X=2)+3P(X=3)+...+10P(X=10)
The probability that a child gets her or his coat is
P(X=1) = 1/10
To compute the probability that 2 children get their own coat, we notice that there are 10! possible permutations of coats. The two children can get their coat in only one way, the other 8 coats can be arranged in 8! different positions, so the probability that 2 children get their own coat is
P(X=2) = 8!/10! = 1/(10*9) and
2P(X=2) = 2/(10*9)
Similarly, we can see that the probability that 3 children get their own coat is
P(X=3) = 7!/10! = 1/(10*9*8) and
3P(X=3) = 3/(10*9*8*7)
and the expected value of X would be
E[X] = 1/10 + 2/(10*9) + 3/(10*9*8)+...+10/10! = 0.1274
Answer:
y=1/3x-2
Step-by-step explanation:
Plot a point at x=-2 and then for the slope (1/3, rise/run) count up 1 and over 3 starting from -2. This is a line. Y intercept at -2 and x intercept at 6.
5/8 . 3/2 is 15/16
So the answer is D
Answer:
x = 5/4
Step-by-step explanation:
By combining like terms, you get 8x = 10.
Divide the 8 on both sides of the equation.
x = 10/8
This, however, can be simplified by dividing by 2. This ultimately gives us 5/4.
