File:Probability line

Probability in numbers edit

In the real world events cannot be pradicted with total certainty. The best we can do is to say how likely they are to happen.

'Examle 1:

an experement with a coin:'

  • Toss a coin 100 times, how many heads will come up?
  • Probability says that heads have a 1/2 chance, so we would expect 50 heads.
  • But when you actually try it out you might get 48 heads, or 55 heads...or anything realy, but in most cases it will be a number near 50.


Example 2: 5 marbels in a bag:

  • 4 are blue and 1 is red.
  • Probability that blue marble will be picked?
  • number of ways it can happen: 4(there are 4 blues)
  • Total number of outcomes:5(there sre 5 marbels
So the probability = 4/5 =0.5