Mean and median - class-IX
Description: mean and median | |
Number of Questions: 29 | |
Created by: Prajapati Rathore | |
Tags: maths mean and median |
What is the value of mean for the following data:
Marks | No. of Student |
---|---|
$5-14$ | $10$ |
$15-24$ | $18$ |
$25-34$ | $32$ |
$35-44$ | $26$ |
$45-54$ | $14$ |
$55-64$ | $10$ |
Mr. R purchases $20\ kgs$. of Wheat, $10\ kgs.$ of rice and $2\ kgs.$ of ghee every month. If the price of wheat is $Rs. 10$ per kg., price of rice is $Rs. 14$ per kg. and price of ghee is $Rs. 120$ per kg. Find the average price per kg. per month. Arithmetic mean $=$?
If there are two groups containing $30$ and $20$ observations and having $50$ and $60$ as arithmetic means, then the combined arithmetic mean is ________.
What is the value of mean for the following data.
Class interval | Frequency |
---|---|
$350-369$ | $15$ |
$370-389$ | $27$ |
$390-409$ | $31$ |
$410-429$ | $19$ |
$430-449$ | $13$ |
$450-469$ | $6$ |
The following is the distribution of weekly wages of workers in a factory. Calculate the arithmetic mean of the distribution.
Weekly Wages (Rs.) | No. of Workers |
---|---|
$240-269$ | $7$ |
$270-299$ | $19$ |
$300-329$ | $27$ |
$330-359$ | $15$ |
$360-389$ | $12$ |
$390-419$ | $12$ |
$420-449$ | $8$ |
The mean weight of $98$ students is found to be $50$ lbs. It is later discovered that the frequency of the class interval $(30-40)$ was wrongly taken as $8$ instead of $10$. Calculate the correct mean.
Consider the following frequency distribution.
Class Intervals | $0-10$ | $10-20$ | $20-30$ | $30-40$ |
---|---|---|---|---|
Frequency | $8$ | $10$ | $12$ | $15$ |
Arithmetic mean $=$?
Coefficient of variation of a distribution is $60$ and its standard deviation is $21$, then its arithmetic mean is?
Arithmetic mean for grouped data can be calculated by _________.
What needs to be done for calculating mean for a continuous series?
For grouped data, Arithmetic mean by Direct Method =
For grouped data, Arithmetic mean by Assumed Mean Method =
If 150 is divided in the ratio of 2:3:5, the distribution will be ____.
9 times of a number is equal to its square find the number_________.
The arithmetic mean of the first 100 natural numbers is _____.
The mean of a sample of size 10 is 15. If the value of each item is doubled, the mean of the sample will be _______.
The sum of first 10 natural numbers is____.
If the frequency of observations $X _{i}$ is $f _{i} (i = 1, 2, ..... n)$.
Consider following frequency distribution.
Class Intervals | $0-10$ | $10-20$ | $20-30$ | $30-40$ |
---|---|---|---|---|
Frequency | $8$ | $10$ | $12$ | $15$ |
Arithmetic mean $=$?
The mean salary for a group of $40$ females workers is $Rs. 5,200$ per month and that for a group of $60$ male workers is $Rs. 6,800$ per month. What is the combined salary?
The average marks of three batches of students having $70, 50$ and $30$ students respectively are $50, 55$ and $45$. Find the average marks of all the $150$ students, taken together.
Only __________ can be used for all algebraic calculations.
Which of the following statistics would give you the estimate of the typical examination score of a class of 35 students?
Measures of central tendency are _______________.
Three geometric means between 5 and 3125 are___.
The most appropriate average to be used to compute the average rate of growth in population is:
The mean of a sample of size $10$ is $15$. If the value of each item is reduced by $2$, the mean of the sample will be_____.
If the average weight of $150$ students is $60$ kg., what will be the number of boys and girls in the school if the average weight of boys and girls is $70$kg and $55$kg. respectively?
Harmonic mean is a part of _______________.