Arithmetic Mean and Range

Q.

The population of a town 2 years ago was 62500. Since some people migrate to different cities the number of people decreases every year at the rate of 4% per annum. Find its present population. [4 MARKS]

Q.

Brooke has scores of $84,72,90,95,$ and $87$ on her first five quizzes. After taking the sixth quiz, Brookes mean score increased. Which could be Brookes sixth quiz score? Select three options.

1. $85$

2. $90$

3. $83$

4. $86$

5. $92$

Q. A school team won 6 games this year and 4 games last year. What is the percent increase ?

Q. Question 57
For the given data below, calculate the mean of its median and mode.
6, 2, 5, 4, 3, 4, 4, 2, 3.

Q. Fill in the blanks
Question 17
The difference between the highest and the lowest observations of a data is called ___.

Q. Question 3
Which measures of central tendency get affected if the extreme observations on both the ends of a data arranged in descending order are removed?
(a) Mean and mode
(b) Mean and median
(c) Mode and median
(d) Mean, median and mode

Q.

The mean of the three numbers is $10.$ The mean of the other four numbers is $12.$
Find the mean of all the numbers.

Q. Question 65
Find the mean of first six multiples of 4.

Q.

Question 50
Calculate the mean, median and mode of the following data:
5, 10, 10, 12, 13
Are these three equal?

Q.

In a cricket match, the bowler bowls at an average speed of 144 km/hr. The ball travels a distance of 12 m before bouncing. After bouncing, it travels 5 m more with same speed before reaching the batsman. Find the time taken by the ball to reach the batsman after being released from the bowler’s hand.

1. 17/144 s

2. 17/40 s

3. 5/40 s

4. 12/40 s

Q. What is the mean and median of the first five even numbers?

1. 3 and 3
2. 6 and 3
3. 3 and 6
4. 6 and 6

Q. Use the sign of $>,<$ or $=$ in the box to make the statement true.
$23-41+11\square 23-41-11$

Q. Fill in the blanks
Question 28
If the arithmetic mean of 8, 4, x, 6, 2, 7 is 5, then the value of x is ___.

Q. To find the average or mean of a set of data, it has to be arranged either in ascending or descending order only.

1. True
2. False

Q.

If it takes $3$ hours to drive a distance of $192$ km on a motorway, what would be the average speed in km/hr?

1. $576$
2. $482$
3. $64$
4. $52$

Q. Question 13
The mean of three numbers is 40. All the three numbers are different natural numbers. If lowest is 19, what could be the highest possible number of remaining two numbers?
(a) 81
(b) 40
(c) 100
(d) 71

Q. Question 9
The difference between the highest and the lowest observations in a data is its
(a) frequency
(b) width
(c) range
(d) mode

Q.

The heights of $10$ girls were measured in cm and the results are as follows: $135,150,139,128,151,132,146,149,143,141$ now find the height of the tallest girl?

Q. What is the class size of class interval 110 - 115 ?

1. 6
2. 5
3. 3
4. 4

Q.

Define the range of an observation?

Q. A woman spends 30% of her monthly income on food, 40% of the remaining on clothes, conveyance and miscellaneous. 50%of the remaining she saves and rest she keeps for emergency expenses. How much money does she. Save?

Q. Question 55
The following are weights (in kg) of 12 persons:
70, 62, 54, 57, 62, 84, 75, 59, 62, 65, 78, 60
(a) Find the mean of the weights of the people.
(b) How many people weight above the mean weight?
(c) Find the range of the given data.

Q. Question 14
Khilona earned scores of 97, 73 and 88 respectively in her first three examinations. If she scored 80 in the fourth examination, then her average score will be
(a) increased by 1
(b) increased by 1.5
(c) decreased by 1
(d) decreased by 1.5

Q.

Find the mean of the following data

$5,10,15,20,25,30,35,40,45,50$

Q.

Find the mean of the first five multiples of $6$

Q.

The marks $(\mathrm{out}\mathrm{of}100)$ obtained by a group of students in a science test are $85,76,90,85,39,48,56,95,81and75.$ Find the highest marks obtained by the students.

Q. Question 9(v)
The height of 10 girls were measured in cm and the results are as follows:
135, 150, 139, 128, 151, 132, 146, 149, 143, 141
How many girls have heights more than the mean height?

Q. What is the arithmetic mean of first five prime numbers ?

1. 6.2
2. 5.2
3. 6.5
4. 5.6

Q. Use the sign of $>,<$ or $=$ in the box to make the statement true.
$39+(-24)-\left(15\right)\square 36+(-52)-(-36)$

Q.

Find the arithmetic mean of 2, 4, 6, 8, 10.

1. 6

2. 4

3. 5

4. 3