Advertisements
Advertisements
प्रश्न
Let `barx` be the mean of x1, x2, ..., xn and `bary` the mean of y1, y2, ..., yn. If `barz` is the mean of x1, x2, ..., xn, y1, y2, ..., yn, then `barz` is equal to ______.
पर्याय
`barx + bary`
`(barx + bary)/2`
`(barx + bary)/n`
`(barx + bary)/(2n)`
उत्तर
Let `barx` be the mean of x1, x2, ..., xn and `bary` the mean of y1, y2, ..., yn. If `barz` is the mean of x1, x2, ..., xn, y1, y2, ..., yn, then `barz` is equal to `underlinebb((barx + bary)/2)`.
Explanation:
Given, `sum_(i = 1)^n x_i = nbarx` and `sum_(i = 1)^n y_i = nbary` ...(i) `[∵ barx = (sum_(i = 1)^n x_i)/n]`
Now, `barz = ((x_1 + x_2 + ... + x_n) + (y_1 + y_2 + ... + y_n))/(n + n)`
= `(sum_(i = 1)^n x_i + sum_(i = 1)^n y_i)/(2n)`
= `(nbarx + nbary)/(2n)` ...[From equation (i)]
= `(barx + bary)/2`
APPEARS IN
संबंधित प्रश्न
Give one example of a situation in which
(i) the mean is an appropriate measure of central tendency.
(ii) the mean is not an appropriate measure of central tendency but the median is an appropriate measure of central tendency.
Find the mean of first five natural numbers .
Numbers 50, 42, 35, 2x + 10, 2x − 8, 12, 11, 8 are written in descending order and their
median is 25, find x.
If the ratio of mode and median of a certain data is 6 : 5, then find the ratio of its mean and median.
If the mean of 2, 4, 6, 8, x, y is 5, then find the value of x + y.
If the difference of mode and median of a data is 24, then find the difference of median and mean.
For which set of numbers do the mean, median and mode all have the same value?
The median of the data 78, 56, 22, 34, 45, 54, 39, 68, 54, 84 is ______.
Obtain the mean of the following distribution:
| Frequency | Variable |
| 4 | 4 |
| 8 | 6 |
| 14 | 8 |
| 11 | 10 |
| 3 | 12 |
Ten observations 6, 14, 15, 17, x + 1, 2x – 13, 30, 32, 34, 43 are written in an ascending order. The median of the data is 24. Find the value of x.
