stat1301test_makeup_sol

# stat1301test_makeup_sol - 11/12 THE UNIVERSITY OF HONG KONG...

This preview shows pages 1–3. Sign up to view the full content.

11/12 p. 1 THE UNIVERSITY OF HONG KONG DEPARTMENT OF STATISTICS AND ACTUARIAL SCIENCE STAT1301 Probability and Statistics I Class Test Solution (Makeup) A n s w e r a l l q u e s t i o n s . T i m e a l l o w e d : 1 h o u r 1. [20 marks] Denote A , B , W as three events. The event W occurs with probability 0.4. If A occurs, then W occurs with probability 0.6. If A does not occur and B occurs, then W occurs with probability 0.1. If neither A nor B occurs, then W occurs with probability 0.5. Moreover, if A does not occur, then B occurs with probability 0.3. (a) Draw a tree diagram to describe the possible situations. (b) Determine . () A P Ans: (a) W W c A W c B B c A c W c p 1 – p 0.6 0.4 0.3 0.7 0.1 0.9 0.5 0.5 (b) From the tree diagram in part (a), ( )( ) ( ) 38 . 0 22 . 0 5 . 0 7 . 0 1 . 0 3 . 0 1 6 . 0 + = × + × × + = p p p W P Solving 38 . 0 22 . 0 4 . 0 + = = p W P gives 0909 . 0 22 . 0 38 . 0 4 . 0 = = = p A P

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
11/12 p. 2 2. [30 marks] A machining operation produces bearings independently with diameters that are normally distributed with mean 76.5 mm and standard deviation 0.3 mm. Specifications require the bearing diameters to lie in the range from 76.05mm to 77.25 mm. Those outside this range
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 01/16/2012 for the course STAT 1301 taught by Professor Smslee during the Fall '08 term at HKU.

### Page1 / 4

stat1301test_makeup_sol - 11/12 THE UNIVERSITY OF HONG KONG...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online