# How do you find the mean, median, and mode of the data set: 15, 13, 9, 9, 7, 1, 11, 10, 13, 1, 13?

May 6, 2017

The mean is the average, equal to $\text{Sum of all the data"/"Number of Data Points}$.

The median is the central number of a set ordered least to greatest.

The mode is the number that appears most frequently.

#### Explanation:

Mean:

Sum of all the data:
$15 + 13 + 9 + 9 + 7 + 1 + 11 + 10 + 13 + 1 + 13 = 102$

Number of data points: $11$

$\frac{102}{11} = 9.272727 \ldots \mathmr{and} 9 \frac{3}{11}$

Median:

The data set in order:
$1 , 1 , 7 , 9 , 9 , 10 , 11 , 13 , 13 , 13 , 15$

Cross out outer ones until you fine the middle:
cancel(1),1,7,9,9,10,11,13,13,13,cancel(15
cancel(1),cancel(1),7,9,9,10,11,13,13,cancel(13),cancel(15
cancel(1),cancel(1),cancel(7),9,9,10,11,13,cancel(13),cancel(13),cancel(15
cancel(1),cancel(1),cancel(7),cancel(9),9,10,11,cancel(13),cancel(13),cancel(13),cancel(15
$\cancel{1} , \cancel{1} , \cancel{7} , \cancel{9} , \cancel{9} ,$10,cancel(11),cancel(13),cancel(13),cancel(13),cancel(15

Median = 10

Mode:

The number 13 appears 3 times, which is more than any other number.

Mode: 13