M L Aggarwal Solutions for Exercise 1: EXERCISE 20.1

Five people were asked about the time in a week they spend in doing social work in their community. They said $10,\mathrm{}7,\mathrm{}13,\mathrm{}20\mathrm{}$ and $\mathrm{}15\mathrm{}$ hours, respectively. Find the mean (or average) time in a week devoted by them for social work.

The mean of $5$ observation is $15$. If the mean of the first three observations is $14$ and that of the last three is $17$, find the third observation.

A student scored the following marks in $11$ questions of a question paper: $7, 3, 4, 1, 5, 8, 2, 2, 5, 7, 6$. Find the median marks.

A group of students was given a special test in Mathematics. The test was completed by the various students in the following time in (minutes):

                       $24,30,28,17,22,36,30,19,32,18,20,24.$

In a Science test given to a group of students, the marks scored by them (out of $100$) are $41, 39, 52, 48, 54, 62, 46, 52, 40, 96, 42, 40, 98, 60, 52$. Find the mean and median of this data.

The points scored by the team of kabaddi in a series of matches are as follows:
$17,\mathrm{}2,\mathrm{}7,\mathrm{}27,\mathrm{}15,\mathrm{}5,\mathrm{}14,\mathrm{}8,\mathrm{}10,\mathrm{}24,\mathrm{}48,\mathrm{}10,\mathrm{}8,\mathrm{}7,\mathrm{}18,\mathrm{}28$
Find the median of the points scored by the team.

The following observations have been arranged in ascending order. If the median of the data is $47.5$, find the value of x.

The following observations have been arranged in ascending order. If the median of the data is $13$. Find the value of x: