Question 1 :
Findthe arithmetic mean of data for the following set of numbers ${23, 45, 34, 43,12, 2, 17, 9, 10}$
Question 2 :
The attendance of a class of 45 boys for 10 days is given as 40, 30, 35, 45, 44, 41, 38, 44 and 41 then the mean attendance of a class is
Question 3 :
If the mean of $x,x+2,x+4,x+6$ and $x+8$ is $1$, what is the average of the last three numbers?
Question 4 :
The mean of $10$ observations is $16.3$. By an error one observation idis registered as $32$ instead of $23$. Then, the correct mean is
Question 5 :
There are four natural numbers. The average of any three numbers is added in the fourth number and in this way, the numbers $29, 23, 21$and $17$ are obtained. One of the numbers is
Question 6 :
The average of marks of $12$ students is $15$. The marks of a student who scored zero were wrongly taken as $18$ and average was determined. The correct average marks is _________.
Question 7 : If the arithmetic mean of the following data is $7$, then $a+b$ =<br><br><table class="wysiwyg-table"><tbody><tr><td>$x_i$</td><td>4</td><td>6</td><td>7</td><td>9</td></tr><tr><td>$f_i$</td><td>$a$</td><td>4</td><td>$b$</td><td>5</td></tr></tbody></table>
Question 8 :
The following observations have been arranged in ascending order. If the median of the data is $78$ find the value of $x\: $.<br/>$44,47,63,65, x+13, 87,93, 99,110.$<br/>
Question 9 :
The average of 75 numbers is calculated as 35. If each number is increased by 5, then the new average is
Question 10 :
The average of $6$ observations is $12$. A new seventh observation is included and the new average is decreased by $1$. The seventh observation is
Question 11 :
The following observations have been arranged in ascending order. If the median of the data is $78$, find the value of $x$.<br/>$44, 47, 63, 65, x + 13, 87, 93, 99, 110$.
Question 12 :
The mean of $15$ observations is $32$. Find the resulting mean. if each observation is decreased by $7$ is $25$<br/>
Question 13 :
Of the four numbers, whose average is $60$, the first is one-fourth of the sum of the last three. The first number is:
Question 14 :
Find the mean of the following data :<br/>$30, 32, 24, 34. 26, 28, 30. 35, 33, 25$
Question 15 :
Wheat was purchases in the fist year at Rs 9 / kg in second year at Rs 10/kg and in the third year at Rs 11/kg ,if each year Rs 990 were spend in purchasing wheat the average cost of wheat during the three year is nearly 
Question 16 :
The average(arithmetic mean) of six numbers is $3$. If the average of the least and the greatest of these numbers is $5$, which set of four numbers can't represent the other four numbers?
Question 17 :
The mean weight of $25$ students of a class is $48$ kg. If the mean weight of first $13$ students is $ 50$ kg. and the last $13$ students is $ 46$ kg. Find the weight of the 13$^{th}$ student.
Question 18 :
A school has 20 teachers one of them retires at the age of 60 years and a new teacher replaces himthis change reduces the average age of new teacher
Question 19 :
The average weight of $20$ students was calculated $70$ kg.It was later discovered that one weight was misread as $70$ instead of $90$, the correct average in kg is<br>
Question 20 :
The average score of a class of boys and girls in an examinations is A. The ratio of boys and girls in the class is 3 : 1 if the average score of the boys is (A + 1), the average score of the girls is
Question 21 :
If the first and the second letters of the word MISJUDGEMENTS are interchanged with the last and the second last letters respectively, and similarly the third and the fourth letters are interchanged with the third and the fourth letters from the last respectively , and so on,then what will be the fifth letter to the right of the third letter from the left end?
