Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
132 views
in Statistics by (115k points)
closed by

In the following table, x is a discrete random variable and p(x) is the probability density. The standard deviation of x is

X

1

2

3

P(x)

0.3

0.6

0.1


1. 0.18
2. 0.36
3. 0.54
4. 0.6

1 Answer

0 votes
by (152k points)
selected by
 
Best answer
Correct Answer - Option 4 : 0.6

Explanation:

For discrete random variable

Mean = μ = E(x) = ∑ xP(x)

= 1 × 0.3 + 2 × 0.6 + 3 × 0.1 = 1.8

And E(x2) = ∑x2P(x) = 1 × 0.3 + 22 × 0.6 + 32 × 0.1 = 3.6

Then variance V = E(x2) – [E(x)]2 = 3.6 – (1.8)2 = 0.36

Then, standard deviation  \(= \sqrt V = \sqrt {0.36} = 0.6\)

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...