A furniture store bought a couch for $425 and marked the price up by 70%. Angela bought the couch with a 6% tax. How much did An
2 answers:
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Answer:
We can find the second moment given by:
And we can calculate the variance with this formula:
And the deviation is:
Step-by-step explanation:
For this case we have the following probability distribution given:
X 0 1 2 3 4 5
P(X) 0.031 0.156 0.313 0.313 0.156 0.031
The expected value of a random variable X is the n-th moment about zero of a probability density function f(x) if X is continuous, or the weighted average for a discrete probability distribution, if X is discrete.
The variance of a random variable X represent the spread of the possible values of the variable. The variance of X is written as Var(X).
We can verify that:
And
So then we have a probability distribution
We can calculate the expected value with the following formula:
We can find the second moment given by:
And we can calculate the variance with this formula:
And the deviation is: