Topics

General Knowledge
General Science
General English
Aptitude
General Computer Science
General Intellingence and Reasoning
Current Affairs
Exams
Elementary Mathematics
English Literature

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) \( \Large \sqrt{\frac{99}{12}} \)

Correct Answer:


B) \( \Large \frac{3}{2}\sqrt{33} \)

Description for Correct answer:
Given, \( \Large \sigma^{2}_{10}=\frac{99}{12}=\frac{33}{4} \)

=> \( \Large \sigma_{10}=\frac{\sqrt{33}}{2} \)

SD of required series = \( \Large 3\sigma_{10}=\frac{3\sqrt{33}}{2} \)

Part of solved Statistics questions and answers : >> Elementary Mathematics >> Statistics

Comments

Similar Questions

1). 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). \( \Large \frac{2^{2n}}{ \left(n+1\right) } \)

2). 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). \( \Large \frac{c^{2}}{a^{2}}\sigma \)

3). For a series the value of mean deviation is 15, the most likely value of its quartile deviation is

A). 12.5

B). 11.6

C). 13

D). 9.7

4). If \( \Large \overline{x} \) is the arithmetic mean of n independent variates \( \Large x_{1},\ x_{2},\ x_{3}.....,\ x_{n} \) each of the standard deviation \( \Large \sigma \), the variance \( \Large \overline{x} \) is

A). \( \Large \frac{\sigma^{2}}{n} \)

B). \( \Large \frac{n\sigma^{2}}{2} \)

C). \( \Large \frac{\left(n+1\right)\sigma^{2}}{3} \)

D). None of these

5). Coefficient of skewness for the values median \( \Large = 18.8,\ Q_{1} = 14.6,\ Q_{3} = 25.2 \) is

A). 0.2

B). 0.5

C). 0.7

D). None of these

6). The 7th percentile is equal to

A). 7th decile

B). \( \Large Q_{3} \)

C). 6th decile

D). None of these

7). Consider the following statements:
1. The values of median and mods can be determined graphically.
2. Mean, median and mode have the same unit.
3. Range is the best measure of dispersion
which of these is/are correct?

A). (1) alone

B). (2) alone

C). Both (2) and (3)

D). None of these

8). If the points (1, 1), (-1, 1), \( \left( -\sqrt{3}, \sqrt{3} \right) \) are the vertices of a triangle, then this triangle is:

A). right angled

B). isoscels

C). Equilateral

D). none of these

9). The length of altitude through A of the triangle ABC where A = (-3, 0), B = (4, -1), C = (5, 2) is:

A). \( \Large \frac{2}{\sqrt{10}} \)

B). \( \Large \frac{4}{\sqrt{10}} \)

C). \( \Large \frac{11}{\sqrt{10}} \)

D). \( \Large \frac{22}{\sqrt{10}} \)

10). If orthocentre and circumcentre of triangle are respectively (1, 1) and (3, 2) then the co-ordinates of its centroid are:

A). \( \Large \left(\frac{7}{3},\ \frac{5}{3}\right) \)

B). \( \Large \left(\frac{5}{3},\ \frac{7}{3}\right) \)

C). (7, 5)

D). none of these