Answer:
70
Step-by-step explanation:
If you use Pascal's Triangle, you will need 9 lines, since there are 9 terms in a binomial raised to the 8th power. Those 9 terms are:
1, 8, 28, 56, 70, 56, 28, 8, 1
The first expansion through the one we need are below (I hope you know how to use Pascal's Triangle!):
Answer:
Step-by-step explanation:
In statistics and probability analysis, the expected value "is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values".
The variance of a random variable Var(X) is the expected value of the squared deviation from the mean of X, E(X).
And the standard deviation of a random variable X is just the square root of the variance.
Let X be a random variable which denotes the money you may win or lose on each spin.
In the game of roulette, a wheel consists of 38 slots. To play the game, a metal ball is spun around the wheel and is allowed to fall into one of the numbered slots. If the number of the slot the ball falls into matches the number you selected, we win $35; otherwise we lose $1. So we have just one possibility to win and 37 of lose on an individual game.
___________________________
X P(X)
___________________________
35 1/38
-1 37/38
___________________________
In order to calculate the expected value we can use the following formula:
And if we use the values obtained we got:
In order to find the standard deviation we need to find first the second moment, given by :
And using the formula we got:
Then we can find the variance with the following formula:
And then the standard deviation would be given by:
Answer:
0.18203 = 18.203% probability that exactly four complaints will be received during the next eight hours.
Step-by-step explanation:
We have the mean during a time-period, which means that the Poisson distribution is used to solve this question.
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given interval.
A service center receives an average of 0.6 customer complaints per hour.
This means that , in which h is the number of hours.
Determine the probability that exactly four complaints will be received during the next eight hours.
8 hours means that .
The probability is P(X = 4).
0.18203 = 18.203% probability that exactly four complaints will be received during the next eight hours.