The marks scored in a form three maths exam were recorded as follows
69 70 72 40 52 60 22 31 78 53 28 67 63 54 57 48 47 56 55 62
75 38 37 44 62 64 58 39 45 48 65 50 85 46 47 57 35 34 58 64
62 37 41 42 36 54 82 48 53 57 56 72 56 48 44 55 78 59 50 45
a) Make a grouped frequency table with classes 20—29,30—39,40—49,etc (2
I hope you can try to draw a frequency table for question a. For b)the modal distribution is btn(50-59).
C)mean=sum of fx÷sum of the frequency.
D)LCB+(remainder*internal)
What is meant by lcb
To create a grouped frequency table with classes of 20—29, 30—39, 40—49, and so on, we need to count the frequency of each score falling into each class.
First, let's list the scores in ascending order:
22 28 31 34 35 36 37 37 38 39 40 41 42 44 44 45 45 46 47 47 48 48 48 50 50 52 53 53 54 54 55 55 56 56 57 57 58 58 59 60 62 62 62 63 64 64 65 67 69 70 72 75 78 78 82 85
Now we can calculate the frequencies for each class.
Class 20-29:
There are no scores in this range.
Class 30-39:
Scores: 22, 28, 31, 34, 35, 36, 37, 37, 38, 39
Frequency: 10
Class 40-49:
Scores: 40, 41, 42, 44, 44, 45, 45, 46, 47, 47, 48, 48, 48
Frequency: 13
Class 50-59:
Scores: 50, 50, 52, 53, 53, 54, 54, 55, 55, 56, 56, 57, 57, 58, 58, 59
Frequency: 16
Class 60-69:
Scores: 60, 62, 62, 62, 63, 64, 64, 65, 67, 69
Frequency: 10
Class 70-79:
Scores: 70, 72, 75, 78, 78
Frequency: 5
Class 80-89:
Scores: 82, 85
Frequency: 2
So, the grouped frequency table with classes 20—29, 30—39, 40—49, etc., is:
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Class | Frequency
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20-29 | 0
30-39 | 10
40-49 | 13
50-59 | 16
60-69 | 10
70-79 | 5
80-89 | 2
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