To find the mean:
SUM [x * P(x)]
Multiply each x by its respective probability P(x). Add together for a total. This will be your mean.
To find variance:
SUM [x^2 * P(x)] - mean^2
Square each x. Multiply each squared x by its respective probability P(x). Add together for a total. Square the mean. Subtract the squared mean from the total. This will be your variance.
To find standard deviation:
Take the square root of the variance.
Hopefully, this information will help you with problems of this type.
The Sarasota Police department collected data on the number of car accidents ( X ) that occur each day on a certain stretch of route 41. From this data, they derived the probability distribution shown in the table below.
X P(X)
0 0.80
1 0.15
2 0.05
What is the expected mean (average) number of accidents that occur each day
3 answers
answer is 0.33
1 to 6264. find the probability of selecting a number that is not divisible by 1000