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The graph shows a probability distribution.

Which probabilities are equal to 0.2?

Select each correct answer.

 

P(X≤2)

P(X≥4)

P(2≤X≤4)

P(1≤X≤3)

 

 

2.

The graph shows a probability distribution.

P(X≤a)=0.5

What is the value of a?

 

3.5

4

4.5

5

 

THAnk YoU!!!!

 May 21, 2019
 #1
avatar+106535 
+2

First one

 

P(X≤2)  = (1/2)(2) (0.2)  = 0.2

P(X≥4)  =  (1/2)(1)(0.4)  = 0.2

P(2≤X≤4)  =  1 - P(X≤2) - P(X ≥ 4)  =  1 - 0.2 - 0.2  =  0.6

P(1≤X≤3)  = P(X≤3)  - P(X ≤1) = (1/2)(3)(0.3) - (1/2) (1) (0.1) =  0.4

 

 

Second one

 

a = 4

 

To see why......draw a vertical line at X = 4

This will form two trapezoids  with bases   4  and 1  and height .20

 

So....the area  of one of these trapezoids  =  (1/2)(.20) (4 + 1)  =  .10 * 5  =  0.5

 

So  P(X ≤ 4)  = .50

 

 

cool cool cool

 May 21, 2019

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