Probability and Measures of Central Tendency

The marks obtained by 25 pupils on a test are shown below.

3, 4, 5, 6, 5

5, 1, 2, 3, 3

4, 7, 5, 1, 5

2, 5, 6, 5, 4

6, 4, 5, 4, 3

Prepare a frequency distribution table and use it to determine its mode.

(a)  

The marks obtained by 25 pupils on a test are shown below.

3, 4, 5, 6, 5

5, 1, 2, 3, 3

4, 7, 5, 1, 5

2, 5, 6, 5, 4

6, 4, 5, 4, 3

Calculate the median score.

(a)  

The marks obtained by 25 pupils on a test are shown below.
3, 4, 5, 6, 5
5, 1, 2, 3, 3
4, 7, 5, 1, 5
2, 5, 6, 5, 4
6, 4, 5, 4, 3
A pupil is chosen at random from the group of pupils. What is the probability that the pupil's mark is greater than 5?


(a)  

Gary has taken an aptitude test 8 times and his scores are 96, 98, 98, 105, 36, 87, 95, and 93.

His mean score is given as

(a)  

A police station kept records of the number of road traffic accidents in their area each day for 100 days. The figures show the number of accidents per day.

Find the mean number of accidents per day.

(a)  

Find the mode of the data set;

Identify the outlier, and

Find the mode excluding outliers:

100, 100, 100, 20, 120, 90.

• 110, 120, 100

• 100, 100, 100

• 20, 100, 20

• 100, 20, 100

Most frequent occurring value in a series is called

• Mode

• Median

• Mean

• None of these

The number of students in different classes of a school are 33, 38, 48, 33, 34, 34, 33 and 24. The mode of this data is

• 24

• 34

• 33

• 48

Out of 5 brands of chocolates in a shop, a boy has to purchase the brand which is most liked by children. What measure of central tendency would be most appropriate if the data is provided to him?

• Mean

• Mode

• Median

• Any of the three

In a school, only 2 out of 5 students can participate in a quiz. What is the chance that a student picked at random makes it to the competition?

• 20%

• 40%

• 60%

• 80%