Question 7:Diagram below shows the marks obtained by a group of 30 students in a history test.(a) Using data in diagram above and a class interval of 5 marks, complete the table in the answer space.(b) Based on the completed table in part (a)(i) find the modal class,(ii) calculate the mean mark obtained by the … Read more

(A) Variance and Standard Deviation For Grouped Data (without Class Interval) Example 2: The data below shows the numbers of children of 30 families: Number of child 2 3 4 5 6 7 8 Frequency 6 8 5 3 3 3 2 Find the variance and standard deviation of the data. Solution: Mean  x ¯ … Read more

Interquartile Range of Grouped Data (without Class Interval) Example 2:  The table below shows the marks obtained by a group of Form 4 students in school mid-term science test. Determine the interquartile range of the distribution. Solution: Lower quartile, Q1 = the   1 4 ( 24 ) th observation   = the 6thobservation   = … Read more

Range of Grouped Data (with Class Interval) Example 2: The grouped frequency distribution was obtained from 100 students regarding the scores in their test shown as below. Find the range of the data. Solution: Range =midpoint of the highest class −midpoint of the lowest class Range= 35+39 2 − 5+9 2    =37−7    =30

(A) Median of Grouped Data (without Class Interval) Example 1: The frequency table shows the marks obtained by 40 students in a biology test.Solution: Median = T n + 1 2 = T 40 + 1 2 = T 20 1 2 = 60 ← ( 20 1 2 th term is 60)