Introduction to averages - class-V
| Description: introduction to averages | |
| Number of Questions: 95 | |
| Created by: Anumati Koshy | |
| Tags: average binomial theorem, sequence and series sequence, progression and series sequences and series maths arithimetic progression |
The $A.M.$ of the observations $1.3.5,3.5,7,9,.,(2n-1)(2n+1) (2n+3)$ is $(\forall\ n\ \in\ N)$
The mean of ${1^{2,}}{2^2},{3^2},{4^2},{5^2},{6^2},{7^2}$ is:
The A.M. of a + 2, a, 2-a is
Find the mean of $ 43,54,64,53,36$
The arithmetic mean of $1 + \sqrt { 2 }$ and $7 + 5 \sqrt { 2 }$ is $\sqrt { a } + \sqrt { b }$ . Then $a - b =$
The airthmatic mean of $1 + \sqrt { 2 }$ and $7 + 5 \sqrt { 2 }$ is $\sqrt { a } + \sqrt { b }$ . Then a $- b =$
Mean of the first $n$ terms of the A.P. $a, (a + d), (a + 2d), ........$ is
If the arithmetic mean of $6, 8, 5, 7, x$ and $4$ is $7,$ then $x$ is
Find the Arithmetic mean between 24 and 36
The arithmetic mean of $12$ and $20$ is :
Find the AM between $20$ and $26$.
The arithmetic mean of 5, 6, 8, 9, 12, 13, 17 is
If each observation is multiplied by $\displaystyle \frac{1}{3}$ then the mean of the new data will de
The mean of $x, y, z$ is $y$, then $x + z = .............$
The arithmetic mean of first five natural number is
The arithmetic mean between $2+\sqrt {(2)}$ and $2-\sqrt {(2)}$ is
Find the arithmetic mean of the progression $2, 4, 6, 8, 10.$
What is the arithmetic mean of the progression $11, 22, 33, 44, 55, 66, 77?$
Find the arithmetic mean of first $10$ natural numbers.
Find AM of first $250$ natural numbers.
If $n^{th}$ term of AP is $4n+1$, then AM of $11^{th}$ to $ 20^{ th}$ terms is
If $n^{th}$ term of AP is $t _n=4n+1$. Find mean of first $10$ terms.
Find AM of multiple of $3$ from natural numbers $1$ to $100$.
The arithmatic mean of $4,6,8$ is
Find AM of $ 3$ digit even numbers between $1$ to $500$.
Find AM of divisors of $100$.
If the nth term of AP is $2n+5$. Then find the AM of first $38$ terms.
The AM of multiple of $5$ from numbers $1$ to $500$ is
The Sum of three numbers in AP is $75$, and product of extremities is $609$. The numbrs and AM of 1st two numbers is
If the Arithmetic mean of $8, 6, 4, x, 3, 6, 0$ is $4$; then the value of $x =$
Arithmetic mean of $2$ and $8$ is
The arithmetic mean of the squares of the first $n$ natural numbers is
The middle terms , if four different numbers are in proportion are called ______ .
The arithmetic mean between $\cfrac { x+a }{ x } $ and $\cfrac { x-a }{ x } $ when $x\ne 0$, is (the symbol $\ne$ means "not equal to"):
The arithmetic mean (average) of a set of $50$ numbers is $38$. If two numbers, namely, $45$ and $55$, are discarded, the mean of the remaining set of numbers is :
If $A _1,A _2$ be two arithmetic means between $\dfrac{1}{3}$ and $\dfrac{1}{24}$, then their value are
Sum of $4$ numbers in GP is $60$. And the AM of first and last no. is $18$ find the first term and common difference of the GP
The A.M. of the observations $1.3.5, 3.5.7, 5.7.9,...,(2n-1)(2n+1)(2n+3)$ is $(\forall n\in N)$
If $n\ AM's$ are inserted between $1$ and $31$ and ratio of ${7}^{th}$ and $(n-1)^{th}$ $A.M.$ is $5:9$ then $n$ equals ?
In a Maths test the average score of the $10$ girls in a class is $15$ and the average score of the $15$ boys is $10$. The average score of the class in the test is
Mean deviation of first $7$ natural no. about their A.M. is?
The ratio of sum of n arithmetic means between two given numbers to that of single arithmetic mean between them id
If $\cfrac {a^n+b^n}{a^{n-1}+b^{n-1}}$ is the AM between a and b, then the value of n is
Find the average of the following set of scores $253,124,255,534,836,375,101,443,760$
The average age of $30$ girls. is $13\ yr$. The average of first $18$ girls is $15\ yr$. Find out the average age of remaining $12$ girls?
A student bought $4$ books for $Rs.120$ from one book shop and $6$ books for $Rs.150$ from another. The average price (in rupees), he paid per book was:
Let $(1-2x+3x^{2})^{10}=a _{0}+a _{1}x+a _{2}x^{2}+....+a _{n}x^{n},a _{n}\neq 0$, then the arithmetic mean of $a _{0},a _{1},a _{2},....a _{n}$ is
If $a,b,c,d,e,f$ are $A.M.s$ between $2$ and $12$ then $a+b+c+d+e+f$ is equal to
The average height of 25 boys is 1.4 m. When 5 boys leave the group, then the average height increases by 0.15 m. What is the average height of the 5 boys who leave?
The average age of 36 student in a group is 14 years. When teacher's age is included to it, the average increases by one. What is the teacher's age in years?
The sum of first $n$ natural numbers is given by the expression $(2n^{2}+3n)$. The mean of the given numbers is
The average weight of 45 students in a class is 25 kg. Five of them whose average weight is 48 kg leave the class and other 5 students whose average weight is 54 kg join the class. What is the new average weight (in kg) of the class?
If n A.M.'s are inserted between 3 and 17 such that the ratio of the last mean to the first mean is 3:1, then the value of n is
Four numbers are in proportion. The sum of the square of the four numbers is $50$ and the sum of the means is $5$. The ratio of first two terms is $1 : 3$. What is the average of the four numbers ?
Average of first ten prime numbers is :
A line is such that the algebraic sum of the perpendicular on it from a number of point is zero. The line always passes through a fixed point that is
Coefficient of variance of a distribution is 60% and the standard deviation is 25. The arithmetic mean of the distribution is
If the arithmetic mean of the numbers $x _{1}, x _{2}, x _{3}.......,x _{3}$ is $\overline{X}$, then the arithmetic mean of numbers $ax _{1}+b, ax _{2}+b, ax _{3}+b,........, ax _{n}+b$, where $a, b$ are two constants would be
The average score of a cricketer for 10 matches is 42, find the average for last four matches :
If the total incomes of $M,N,O,P$ are in the rate a $2:3:4:5$ and the total income of $M$ is $Rs\ 8000$ , then find approximate average salary of all four?
The artimetic mean of $2 sin 2^o, 4 sin 4^o, 6sin6^o,...,180sin 180^o$ is equal to
Arithmetic Mean is ______ affected by extreme values.
Suppose a population $A$ has $100$ observations $101,102...200$ and other population $B$ has $100$ observations $151,152...250$.
The mean of 2, 7, 6 and x is 15 and the mean of 18, 1, 6, x and y is 10. What is the value of y ?
Sum of $50$ A.M. between $20$ and $30$ is :
$11\,AM's$ are inserted between $28$ and $10$ then ${6}^{th}\,AM$ is
The mean of $3$ observations is $12$ and mean of $5$ observations is $4$ the combined mean is
The sum of $9$ numbers is $246$. If the average of three of them is $24$, what is the average of the remaining numbers?
A boy draws n squares with sides $1,2,3,4,5....$ in inches.The average area covered by these n squares will be:
The mean marks of $120$ students is $20$. It was later discovered that two marks were wrongly taken as $50$ and $80$ instead of $15$ and $18$. The correct mean of mark is
The Arithmetic mean of first $5$ whole numbers.
For a certain frequency table which has been partly reproduced here, the arithmetic mean was found to be Rs.28.07
| Income (in Rs.) | 15 | 20 | 25 | 30 | 35 | 40 |
|---|---|---|---|---|---|---|
| Number of workers | 8 | 12 | ? | 16 | 3 | 10 |
If he total number of workers is 75, then the missing frequencies are?
The antithetic mean of the masks is _________.
let a and b be the two different natural numbers whose harmonic mean is 10 then their arithmatic mean is ______.
If 25 is the arithmetic mean between x and 46, then find x.
The arithmetic mean of first ten natural numbers is
If AM between $\displaystyle p^{th}$ and $\displaystyle q^{th}$ terms of an AP be equal to the AM between $\displaystyle r^{th}$ and $\displaystyle s^{th}$ term of the AP, then $p + q$ is equal to
The arithmetic mean of 1, 2, 3, ..., n, is
Find the arithmetic mean of the series $1, 3, 5,...........
(2n - 1)$
Find the arithmetic mean of the series: $1,3,5 ........... (2n - 1)$
What is the average of the first $300$ terms of the given sequence?
$1, -2, 3, -4, 5, -6, ....., n.(-1)^{n + 1}$
The A.M. of 'n' observations is M. If the sum of $(n - 4)$ observation is 'a', what is the mean of remaining $4$ observations?
The mean of five numbers in AP is $89$. The product of first and last terms is $7885$. The AM of first, third and fifth term is
The sum of four numbers in AP is $176$. The product of 1st and last is $1855$. The mean of middle two is
The arithmetic mean of 1, 8, 27, 64, ....... up to n terms is given by
Say true or false.
If the arithmetic mean of n numbers of a series is $\overline{x}$ and the sum of the first (n-1) numbers is k, then the nth number is
The arithmetic mean (average) of the first $n$ positive integers is
The mean of the cubes of the first $n$ natural numbers is :
If the arithmetic mean of $n$ numbers of a series is $\bar{x}$ and sum of the first $(n - 1)$ numbers is $k$, then which one of the following is the nth number of the series ?
The mean marks got by $300$ students in the subject of statistics was $45$. The mean of the top $100$ of them was found to be $70$ and the mean of the last $100$ was known to be $20$, then the mean of the remaining $100$ students is
If $a _{1}=0$ and $a _{1}, a _{2}, a _{3}, ...., a _{n}$ are real numbers such that $|a _{i}|=|a _{i-1}+1|$ for all $i$ then the Arithmetic mean of the numbers $a _{1}, a _{2}, ..., a _{n}$ has value $x$ where