The time taken (in minutes) to complete a homework by 8 students in a day are given by 38,40,47,44,46,43,49,53. Find the coefficient of variation.

The time taken (in minutes) to complete a hoework by 8 students in a day are given by 38,40,47,44,46,43,49,53. Find the coefficient of variation.

The time taken by 50 students to complete a 100 meter race are given below. Find its standard deviation.

A bar magnet makes 40 oscillations per minute in an oscillation magnetometer. An identical magnet is demagnetized completely and is placed over the magnet in the magnetometer. Find the time taken for 40 oscillations by this combination. Neglect any induced magnetism.

Kavitha thought of constructing 2 more rooms in her house. She enquired about the labour. She came to know that’s 6 men and 8 women could finish this work in 14 days. But she wishes to complete that work in only 10 days. When she enquired, she was told that 8 men and 12 women could finish the work in 10 days. Find out how much time would be taken to finish the work if one man or one woman worked alone.

The marks of 30 students of a class of 10 in a test (out of 75) are given below 40, 21, 50, 37, 42, 37, 38, 42, 49, 52, 38, 53, 57, 47, 29, 59, 61, 33, 17, 17, 39, 44, 42, 39, 14, 7, 27, 19, 54, 51. Form a frequency table with equal class intervals.