Write the comulative frequency of class interval 30-40

The mean of the following distribution is 52 and the frequency of class interval 30-40 is f. Find f.

In the following frequency distribution, the frequency of the class interval (40-50) is not known. Find it, if the arithmetic mean of the distribution is 52. {:("Wages(Rs.)",10-20,20-30,30-40,40-50,50-60,60-70,70-80),("Number of Workes"," "5," "3," "4," "?," "2," "6," "13):}

Define frequency density of a class interval.

For the given distribution, draw the less than and greater than cumulative frequency curves. {:("Class Interval",0-10,10-20,20-30,30-40,40-50,50-60,60-70,70-80),("Frequency",5,3,7,2,14,9,15,10):}

What do you mean by class-frequency ? What is relative class-frequency of any class-interval?

The marks obtained by 32 students of a class are given below. Prepare a frequency table with class intervals 31-40, 41-50, ….. etc.

The marks obtained by 32 students of a class are given below. Prepare a frequency table with class intervals 31-40, 41-50, ….. etc.

In the less than type of ogive the comulative frequency is plotted against