26
MCQ (Single Correct Answer)
When tested, the lives (in hours) of 5 bulbs were noted as follows
$$\text { 1357, 1090, 1666, 1494, } 1623$$
The mean deviations (in hours) from their mean is
A
178
B
179
C
220
D
356
27
MCQ (Single Correct Answer)
Following are the marks obtained by 9 students in a mathematics test
$$50,69,20,33,53,39,40,65,59$$
The mean deviation from the median is
A
9
B
10.5
C
12.67
D
14.76
28
MCQ (Single Correct Answer)
The standard deviation of data $6,5,9,13,12,8$ and 10 is
A
$\sqrt{\frac{52}{7}}$
B
$\frac{52}{7}$
C
$\sqrt{6}$
D
6
29
MCQ (Single Correct Answer)
If $x_1, x_2, \ldots, x_n$ be $n$ observations and $\bar{x}$ be their arithmetic mean. Then, formula for the standard deviation is given by
A
$\Sigma\left(x_i-\bar{x}\right)^2$
B
$\frac{\Sigma\left(x_i-\bar{x}\right)^2}{n}$
C
$\sqrt{\frac{\sum\left(x_i-\bar{x}\right)^2}{n}}$
D
$\sqrt{\frac{\Sigma x_i^2}{n}+\bar{x}^{-2}}$
30
MCQ (Single Correct Answer)
If the mean of 100 observations is 50 and their standard deviation is 5 , than the sum of all squares of all the observations is
A
50000
B
250000
C
252500
D
255000