Data Handlings
Find the range of heights of any ten students of your class.
Heights of 10 students of our class.
= 125, 130, 134, 137, 138, 139, 140, 143, 147, 150
We know
Range = Highest value – Lowest value
The highest value = 150cm
The lowest value = 125 cm
Then,
Range of Heights = Highest value – Lowest value
= 150 – 125
= 25 cm
Organise the following marks in a class assessment, in a tabular form.
4, 6, 7, 5, 3, 5, 4, 5, 2, 6, 2, 5, 1, 9, 6, 5, 8, 4, 6, 7
(i) Which number is the highest? (ii) Which number is the lowest?
(iii) What is the range of the data? (iv) Find the arithmetic mean.
On Arranging in ascending order.
= 1, 2, 2, 3, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 8, 9
Now, we will draw the frequency table of the given data.
< img class="mathsPageImg" src="/Pathanto/image/cl7-3-9.jpg" >(i) From table the highest number is 9.
(ii)From table the lowest number is 1.
(iii) We know that
Range = Highest value – Lowest value
= 9 – 1 = 8
iv)Mean =Then,
Sum of all observation = 1 + 2 + 2 + 3 + 4 + 4 + 4 + 5 + 5 + 5 + 5 + 5 + 6 + 6 + 6 + 6 + 7 + 7
+ 8 + 9 = 100
Total Number of Observation = 20
Mean == 5
The first five Whole numbers are 0, 1, 2, 3, and 4.
Mean =Then,
Sum of the numbers = 0 + 1 + 2 + 3 +4 = 10
Total Number = 5
Mean =58, 76, 40, 35, 46, 45, 0, 100. Find the mean score.
Total runs scored by the cricketer = 58 + 76 + 40 + 35 + 46 + 45 + 0 + 100 = 400
Total number of innings = 8
Then,
Mean =| Player | Game
1 |
Game
2 |
Game
3 |
Game
4 |
| A | 14 | 16 | 10 | 10 |
| B | 0 | 8 | 6 | 4 |
| C | 8 | 11 | Did not Play | 13 |
Now answer the following questions:
(i) Find the mean to determine A’s average number of points scored per game.
(ii) To find the mean number of points per game for C, would you divide the total points by 3 or by 4? Why?
(iii) B played in all the four games. How would you find the mean?
(iv) Who is the best performer?
(ii) To find the mean number for player C, we will divide the total points by 3. Because C played only 3 games.
(iii)We will divide the total points by 4 to find out the mean of B played
Then,
Mean of player B =(vi) Mean of player C =
As we saw average points scored A more than B and C.
So A is the best performer among three.
(i) Highest and the lowest marks obtained by the students.
(ii) Range of the marks obtained
(iii) Mean marks obtained by the group.
Arrange in ascending order,
= 39, 48, 56, 75, 76, 81, 85, 85, 90, 95
(i) The highest marks obtained by the student = 95
The lowest marks obtained by the student = 39
(ii) Range = Highest marks – Lowest marks
= 95 – 39 = 56
(iii) Mean of Marks =1555, 1670, 1750, 2013, 2540, 2820.
Find the mean enrolment of the school for this period.
| Day | Mon | Tue | Wed | Thurs | Fri | Sat | Sun |
|
Rainfall
(in mm) |
0.0 | 12.2 | 2.1 | 0.0 | 20.5 | 5.5 | 1.0 |
(i) Find the range of the rainfall in the above data.
(ii) Find the mean rainfall for the week.
(iii) On how many days was the rainfall less than the mean rainfall.
(i) Range = Highest rainfall – Lowest rainfall
= 20.5 – 0.0= 20.5 mm
(ii) Mean of rainfall =(iii) Monday, Wednesday, Thursday, Saturday and Sunday the rainfall was less than the average rainfall.
135, 150, 139, 128, 151, 132, 146, 149, 143, 141.
(i) What is the height of the tallest girl? (ii) What is the height of the shortest girl?
(iii) What is the range of the data? (iv) What is the mean height of the girls?
(v) How many girls have heights more than the mean height.
On Arranging in ascending order,
128, 132, 135, 139, 141, 143, 146, 149, 150, 151
(i) The height of the tallest girl is 151 cm
(ii) The height of the shortest girl is 128 cm
(iii) Range = Tallest height – Shortest height
= 151 – 128 = 23 cm
(iv) Mean height of the girls =(v) There 5 girls who's heights more than the 141.4 cm