Page 84 - Mathematics Class - X
P. 84
7. The theoretical probability of an event E (a head) = P (H).
Number of outcomes favourable to E 1
P( ) =E =
Number of all possible outcomes of the experiment 2
From Steps 6 and 7, it can be seen that the experimental probability of a head is very close to the theoretical
probability.
This activity can be performed for the occurrence of a tail.
OBSERVATIONS
1. Each group will complete the following table:
Number of times a coin Total number of times
Group
is thrown in a group a head comes up
I 100 a ......
1 =
II 100 a ......
2 =
III 100 a ......
3 =
IV 100 a ......
4 =
...... ...... ......
...... ...... ......
...... ...... ......
...... ...... ......
...... ...... ......
X 100 a ......
10 =
2. Each group will complete the following table:
2 3 4
∑ a ∑ a ∑ a
a 1 = , a + a 2 = i = 1 i = , i = 1 i = , i = 1 i = ,
1
100 200 200 300 400
∑ 5 a i ∑ 6 a i ∑ 7 a i ∑ 8 a i
i = 1 = , i = 1 = , i = 1 = , i = 1 = ,
500 600 700 800
9 10
∑ a i ∑ a i
i = 1 = , i = 1 = ,
900 1000
3. Experimental probability of a head =
1000
82
