question_answer

On the basis of following frequency table find the mean marks:

Marks	20	30	40	50	60	70
Number of student	12	45	48	5	32	40

Answer:

Marks (x)	No. of Students	\[f\times x\]
20	12	240
30	45	1350
40	48	1920
50	5	250
60	32	1920
70	40	2800
Total	N = 182	\[\Sigma fx=8480\]

                                                                                    Mean \[=\frac{\Sigma fx}{N}\] Putting values from table, Mean \[=\frac{8480}{182}=46.59.\]