Arithmetic Mean
Arithmetic Mean: Overview
This topic contains concepts like Mean of Data, Properties of Mean of Data, and Range of Data.
Important Questions on Arithmetic Mean
If we sit like this,
| On the first bench students |
| On the second bench students |
| On the third bench students |
| On the fourth bench students |
| On the fifth bench students |
Average number of students sitting on each bench is _____.
The weights of new-born babies (in ) in a hospital on a particular day are as follows:
Determine the range.
The mean weight of 25 students in a class is 46 kg. If the mean weight of the first 13 students is 42 kg and that of the last 13 students is 49 kg, then the 13th students is _____kg
The average marks scored by 40 students in an examination out of 20 was 16. Since they were very undisciplined during the test, 4 marks were subtracted from each student’s paper. So the new mean marks obtained by the students in the class was_____
The mean average weight of 100 soldiers in the camp is 86 Kg. One of the soldiers’ left the camp and then the mean weight of the remaining soldiers was 86.1 kg. The weight of the soldier who left the camp must be _____ kg.
Shown below are the petrol prices in Bangalore, sampled for 10 weeks starting from 15 May - 01 Nov. The price of petrol on 15 Jun, 1 Jun and 15 May were the same.
| 1 Nov | 15 Oct | 1 Oct | 15 Sep | 1 Sep | 15 Aug | 1 Aug | 15 Jun | 1 Jun | 15 May |
| 70.5 | 73.1 | 74.4 | 75.1 | 77.1 | 79.5 | 80.7 | P | P | P |
If the mean price of petrol during this period was &rupee;76.56, the price of petrol as of 15 June was &rupee;_____.
The wages of 50 employees of a factory is given below.
| 3000 | 4000 | 5000 | 6000 | 7000 | 8000 | 9000 | 10000 |
| ? | 10 | 9 | 7 | 5 | 4 | 2 | 1 |
Their mean salary is &rupee;_____.
The age (in years) of students of a class is given below. The numbers of students who are 16 years old is not known.
15 | 16 | 17 | 18 |
2 | ? | 6 | 1 |
If the mean age is 16.3 years, the number of students in the class is _____.
On a particular day in Portland Public School, the lunch sold by the school canteen to the students of grade 9 is as follows:
School lunch ( in $) | Number of students |
2.50 | 10 |
2.70 | 15 |
2.95 | 20 |
3.20 | 12 |
4.20 | 13 |
The above data is represented in the form of a table to find the total earning from grade 9 students:
Cost of School lunch (in $)$ ({x}_{i)}$ | Number of students$ {(f}_{i)}$ | Total cost (in $)$ {(x}_{i}{f}_{i)}$ |
2.50 | 10 | 25 |
2.70 | 15 | 40.5 |
2.95 | 20 | 59 |
3.20 | 12 | 38.4 |
4.20 | 13 | 54.6 |
The mean earning from the lunch sold on that particular day is $_____. (Round off to 2 decimal places)
In one of the weeks, during the library period the librarian issued reference books to the students of class 12:
Days of the week | Number of copies |
Monday | 16 |
Tuesday | 22 |
Wednesday | 12 |
Thursday | 8 |
Friday | 2 |
Saturday | 0 |
The mean number of the books issued per day during the week is _____.
Five friends went to McDonalds and ordered Econo Meal with different fillings. One of them had McEgg left without paying. The others shared the bill amount.
Econo Meals | Price in &rupee;. |
McAloo Tikki | 109 |
Masala Grill Veg | 125 |
McEgg | 115 |
Chicken McGrill | 124 |
Masala Grill Chicken | 135 |
Each of them will pay &rupee;_____
The box office collection for the movie Transformers – Age of Extinction in USA during the first 9 days of release is given as:
Day | Daily gross ( in dollars) |
1 | 4902 |
2 | 5088 |
3 | 8788 |
4 | 17351 |
5 | 10049 |
6 | 2461 |
7 | 2572 |
8 | 2829 |
9 | 3003 |
The mean income from the movie in the 9 days is _____ dollars. (Round off up to 2 decimal places)
The number of foreign tourists who arrived in India over the last 10 years is given as:
Year | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 |
Number of tourists (in millions) | 3.46 | 3.92 | 4.45 | 5.08 | 5.28 | 5.17 | 5.78 | 6.31 | 6.58 | 6.97 |
The mean of the number of foreign tourists arrival in India in the last 10 years is _____ millions.
Mukesh collected some data and calculated the average of those data. He finds that average is 81 and sum of the observation is thrice of the average.
Therefore, the number of observations = _____
The average weight of the members of the Mehta family is 60 kg and the sum of weights of all family members is 360 kg. So, there are _____ members in Mehta family.
Raju checked his savings for the last few months and found that he has saved &rupee; 51 every month on an average. He has saved a total of &rupee; 255 in all these months. The number of months for which he saved the money is _____.
The average of a set of observations is 45 and the sum of observations is 405.
Then, the number of observations are
The given table shows the number of questions made by Deepa over six months.
Month | January | February | March | April | May | June |
Number of questions | 100 | 80 | 120 | 90 | 100 | 80 |
For each question she gets Rs. 50. What is the average amount Deepa earns in a month?
Every day Bani collects waste from 10 houses. she supplies it to a plant producing bio gas the same day. She gets &rupee; 60 for exchanging 5 kg of waste from the plant administer.
Look at the given table which shows the total collection of waste from 10 houses on various days.
Day | Monday | Tuesday | Wednesday | Thursday | Friday | Saturday |
Weight of waste | 6 kg | 8 kg | 6 kg | 5 kg | 10 kg | 7 kg |
What is the average earning of Bani in a day?
Manu plants a small tree in his pot. At the end of every month he measures the height of the plant above the soil surface and notes down the observation as shown in the table below :
Month | March | April | May | June | July |
Height of plant above the soil surface | 35 cm | 37.2 cm | 39 cm | 42 cm | 42 cm |
The average growth of the plant per month is _____ cm.
