91Ó°ÊÓ

• The mean of a data is: $\text{Mean}=\frac{\text{sumofallthenumbersindata}}{\text{Totalnumberofnumbersindata}}$
  
• The median of a data is calculated by arranging the numbers in data in ascending order then if:

1. The numbers in the data are odd, then the median is the middle term.
2. The numbers in data are even, then the median is the average of the middle term.

• The mode of data is the most repeated number of the data.

Numbers in data are(in ascending order): 2, 5, 9, 10, 17, 17, 18, i.e., there are 7 numbers in data.

Use the formulae mentioned to find mean, median and mode.

$$\begin{gathered} \text{Mean}=\frac{2+5+9+10+17+17+18}{\text{7}} \\ =\frac{78}{7} \end{gathered}$$

Since there are 7 numbers(odd) in data so the median is the middle term that is the 4th number, which is 10.

Thus, the median is 10.

And it can be noticed that 17 is repeated twice and most of the time, i.e. mode of the data is 17.

Thus, the mean of the given data is $\frac{78}{7}$, the median of the given data is 10, and mode of the given data 17.