Statistic Case

Total students = 100

Total left handed = 10

Total right handed = 100 - 10 = 90

= 90

Right handed students

p ( R1 ) x ( 2 R handed )

90 /100 x 89 / 99 = 8010 / 9900 = 0.8091

= 0 .8091

(b) Left handed students

Total left handed students = 10

P ( L1 x (2L ) = 10/100 x 9/99

= 0.1 x 0.0909 = 0.0091

= 0.0091

( c) Right handed other left handed

P ( R1) other left handed = P ( R 1 ) and ( L2 ) or P ( L1 ) and P( R2 )

P = 90/100 x P = 10/99 or 10/100 x 90/99

= ( 0.9 x 0.01010 ) + (0.1 X 0.9091)

= 0.0909 + 0.09091 = 0.1818

= 0.1818

(D) At least right handed

1a + 1c total

0.8091 + 0.1818 = 0.9909

=0.9909

(2) Find the joint propability

P ( AB ) = P ( A ) P ( B/A )

P = ( A ) = 0.4 P ( B/A ) = 0.3P ( AB = ( 0.4 x 0.3 ) = 0.12

= 0.12

(3) Total possible outcome of dice 6x 6 = 36

Propability first throw = 2 = 1

Probability second throw = 1 = 1

Probability for 2 throws = 1/6 x 1/6 = 1/36

= 1/36

(b ) No of ways sum = 7

1 +6 = 7

2+ 5 = 7

3+ 4 = 7

4+ 3 = 7

5+ 2 = 7

6+ 1 =7

Probability total number = 7

= 6/36 = 1/6

= 1/6

(4 ) Coined tossed 4 times outcome recorded for each toss.

HHHT TTTT

HHHH TTTH

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HTHT THTH

HTTH THHT

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