Introduction to Outliers

Q.

Following data shows the marks obtained by $30$ students in a unit test :

$$\begin{gathered} 20,25,30,24,30,25,20,19,15,10,24,25,30,24,19,30,25,15,20,24, \\ 25,30,19,19,25,24,30,19,24,20 \end{gathered}$$

Write the above data in a tabular form using tally marks and answer the following questions :

a) Find the number of students who scored more than $25$ marks.

b) If passing marks are $20$, then how many students got pass in this test ?

c) How many students scored marks between $15$ and $30?$

Q. Find out the outliers in the given dataset : $93,87,6,73,391,101,83$

1. 6 and 391
2. 6
3. 391

Q.

How does an outlier affect the mean of a data set?

Q. Medals won by a school in Inter Sports Competition are as follows:
Year Number of Medals

2005	20
2011	23
2015	18
2017	7
2020	21

Identify the outlier corresponding to the number of medals won in different years.

1. 7
2. 23

Q. If outlier is removed from the data set $5,8,3,9,7,4,27$
The mean of the dataset .

1. will increase
2. will decrease
3. will be same

Q. Given data set: 100, 103, 98, 34, 99, 101, 103, 97, 105

Which of the following statements is true regarding this data?

1. The value 34 is the outlier.
2. The value 105 is the outlier.
3. Multiple outliers exist.
4. No outliers exist.

Q. Kattie's scores on her first six biology tests were:
55, 88, 89, 92, 95, and 98.
Identify the outlier in her scores.

1. 98
2. 55
3. 92
4. 88