A class-interval of 30-40 would have a class symbol of - | 9 | MATHEMATICS | MATHS | S CHAND | Doubtnut

In the class interval 20 - 30, the lower class limit is _______

In the class intervals 30-60, 60-90 the number 90 is included in

Find the class mark of the classes 20 − 30 and 30 − 40.

in the class intervals 40 to 50 and 50 to 60 the number 60 is included in

The following are the scores of two groups of class 9^(th) students in a test of MATHEMATICS.

Write the comulative frequency of class interval 30-40

Given below are the marks obtained by 30 students of a class, Using the class intervals of equal class size in which one class interval is 30-40 (excluding 40), construct a frequency table. {:(42,74,39,48,42,80,35,38,52,81),(31,72,65,58,77,82,79,65,47,30),(64,56,39,48,60,63,72,50,46,35):}

The marks obtained by 40 students are grouped in a frequency table in class intervals of 10 marks each. The mean and the variance obtained from this distribution are found to be 40 and 49, respectively. It was later discovered that two observations belonging to the class interval (21 - 30) were included in the class interval (31 - 40) by mistake. Find the mean and the variance after correcting the error.

Average of the marks in maths of 40 students in a class was 74 . The mean of marks for boys was 72, while their number was 21 . The mean of marks of girls in the class was

If the class intervals of a frequency distribution are 1-10, 11-20, 21-30, …., 61-70 , Then the upper limit of 21-30 is