SaiBook.us Statistics

Home Course Section

Register Enroll Refer

Lesson Example Discussion Quiz: Class Homework

Step-2

Title: Continuous random variable

Grade: 9-a Lesson: S4-L7

Explanation: Hello Students, time to practice and review the steps for the problem.

Lesson Steps

Step	Type	Explanation	Answer
1	Problem	A continuous random variable X has a probability density function \$f(x)=e^-x,0<x<\infty\$ Then P(X > 1)
2	Step	P(X > 1)	\$\int_1^\infty f(x) dx\$
3	Step	Substitute f(x) in the formula	P(X > 1) = \$\int_1^\infty e^-x dx\$
4	Step	Simplification	P(X > 1) = \$-(e^-x)_1^\infty\$
5	Step	After simplification	P(X > 1) = \$-(0-e^-1)\$ = \$1/e\$
6	Step	After simplification	P(X > 1) = 0.368
7		Answer	C

Step

Type

Explanation

Answer

Problem

A continuous random variable X has a probability density function

\$f(x)=e^-x,0<x<\infty\$

Then P(X > 1)

Step

P(X > 1)

\$\int_1^\infty f(x) dx\$

Step

Substitute f(x) in the formula

P(X > 1) = \$\int_1^\infty e^-x dx\$

Step

Simplification

P(X > 1) = \$-(e^-x)_1^\infty\$

Step

After simplification

P(X > 1) = \$-(0-e^-1)\$
= \$1/e\$

Step

After simplification

P(X > 1) = 0.368

Answer

Tutor: Questions

Seq	Type	Question
1	Problem	What did you learn from this problem?
2	Clue	What did you learn from the clues?
3	Hint	What did you learn from the Hints?
4	Step	What did you learn from the Steps?
5	Step	How can we improve the Steps?

Seq

Type

Question

Audio

Problem

What did you learn from this problem?

Clue

What did you learn from the clues?

Hint

What did you learn from the Hints?

Step

What did you learn from the Steps?

Step

How can we improve the Steps?