The total number of participants in a pie eating contest in a country fair .
Find the probability by dividing the frequency of each value by the total number of pies.
\The probability of the participant is
.
Similarlly .
.
.
.
The probability distribution of is
Pies eaten , ![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
Graph :
\Graph the probability distribution.
\The mean value is .
.
The mean value is .
On average, the contests eat pies.
The variance of random variable is
.
.
The variance is .
The standard deviation is .
Substitute .
.
Therefore, the standard deviation is .
The probability distribution of is
Pies eaten , ![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
![]() | \
Graph of the probability distribution is.
\The mean value of a random variable is
.
On average, the contests eat pies.
The variance of a random variable is
.
The standard deviation of a random variable is
.