Tag: shortcut method to find variance and standard deviation
Questions Related to shortcut method to find variance and standard deviation
What will be the relative range, if the spread of items in a given distribution lies between $100$ and $180$kg?
An index is at 100 in 1991. It rises 5% in 1992, falls 6% in 1993,falls 5% in 1994, rises 4% in 1995 and 7% in 1996.The index numbers for all these years with 1991 as base are _______.
The standard deviation of $5$ items is found to be $15$. What will be the standard deviation if the values of all the items are increased by $5$?
The mean of $100$ observations is $18.4$ and sum of sqares of deviations from mean is $1444$, the Co-efficient of variation is ______.
The first quartile of the following observations is
$10, 19, 22, 16, 15, 18, 20, 18, 14, 18, 23$.
The following distribution of ages (in complete years) is obtained for the students of higher secondary.
The mode of the distribution is.
| Age (in years) | 15 | 16 | 17 | 18 | 19 | 20 | 21 |
|---|---|---|---|---|---|---|---|
| Number of students | 12 | 18 | 20 | 10 | 7 | 6 | 2 |
The median for the following distribution is
| X | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|---|---|---|---|---|---|---|---|---|---|---|
| Y | 3 | 6 | 9 | 18 | 20 | 14 | 10 | 10 | 7 | 2 |
The mean of $25$ observations is $73.408$. If one observation $64$ is removed, the revised mean is ______.
The correct relation between variance and standard deviation (S.D) of a variable X is _______.
For comparison of two different series, the best measure of dispersion is _________.