11). The mean value of the median and mean of the add divisions of 360 is
| A). 13 |
| B). 7 |
| C). 6 |
| D). 10 |
|
12). If the mean of n items is \( \Large \overline{x} \) and the sum of any \( \Large \left(n-1\right)\) number is R, then the value of left item is
| A). \( \Large n+\overline{x} \) |
| B). \( \Large n\overline{x}-R \) |
| C). \( \Large \overline{x}+Rn \) |
| D). \( \Large n\overline{x}-nR \) |
|
13). In a class of 50 students, 10 have failed and their average marks are 28. The total marks obtained by the entire class on 2800. The average marks of those who have passed, are
| A). 43 |
| B). 53 |
| C). 63 |
| D). 70 |
|
14). The mean of n observations is \( \Large \overline{x} \). If one observation \( \Large x_{n+1} \) is added, then the mean remains same. The value of \( \Large x_{n+1} \) is:
| A). 0 |
| B). 1 |
| C). n |
| D). \( \Large \overline{x} \) |
|
15). In a class of 100 students, the average amount of pocket money is Rs.35 per student. If the average is Rs.25 for girls and Rs.50 for boys, then the number of girls in the class is
| A). 20 |
| B). 40 |
| C). 60 |
| D). 80 |
|
16). The mean of the n observations \( \Large x_{1},\ x_{2},\ x_{3}.....,\ x_{n} \) be \( \Large \overline{x} \). Then, the mean of n observations \( \Large 2x_{1}+3,\ 2x_{2}+3,\ 2x_{3}+3,.......2x_{n}+3 \) is
| A). \( \Large 3\overline{x}+2 \) |
| B). \( \Large 2\overline{x}+3 \) |
| C). \( \Large \overline{x}+3 \) |
| D). \( \Large 2\overline{x} \) |
|
17). If\( \Large \overline{x}_{1}\ and\ \overline{x}_{2} \) are the mean of two distributions such that \( \Large \overline{x}_{1}\ <\ \overline{x}_{2}\ and\ \overline{x} \) is the mean of the combined distribution, then
| A). \( \Large \overline{x}\ <\ \overline{x}_{1} \) |
| B). \( \Large \overline{x}\ >\ \overline{x}_{2} \) |
| C). \( \Large \overline{x} = \frac{\overline{x}_{1} \times \overline{x}_{2}}{2} \) |
| D). \( \Large \overline{x}_{1}\ <\ \overline{x}\ <\ \overline{x}_{2} \) |
|
18). If the variance of 1, 2, 3, 4, 5,........., 10 is \( \Large \frac{99}{12} \), then the standard deviation of 3, 6, 9, 12, ....., 30
| A). \( \Large \frac{297}{4} \) |
| B). \( \Large \frac{3}{2}\sqrt{33} \) |
| C). \( \Large \frac{3}{2}\sqrt{99} \) |
| D). \( \Large \sqrt{\frac{99}{12}} \) |
|
19). The AM of \( \Large ^{2n+1}C_{0},\ ^{2n+1}C_{2},\ .....^{2n+1}C_{n} \) is
| A). \( \Large \frac{2^{n}}{n} \) |
| B). \( \Large \frac{2^{n}}{n+1} \) |
| C). \( \Large \frac{2^{2n}}{n} \) |
| D). \( \Large \frac{2^{2n}}{ \left(n+1\right) } \) |
|
20). If SD of X is S, then SD of the variable M \( \Large \frac{aX+b}{c} \), where a, b, c are constants, is
| A). \( \Large |\frac{c}{a}|\sigma \) |
| B). \( \Large |\frac{a}{c}|\sigma \) |
| C). \( \Large |\frac{b}{c}|\sigma \) |
| D). \( \Large \frac{c^{2}}{a^{2}}\sigma \) |
|
