Question

Describe what it means for two events to be statistically dependent.

Answer 1

Two events are said to dependent if the outcome or occurrence of the first events affect the outcome or occurrence of the second event so that the probability is changed .

Suppose we have 3 blue marbles and 3 red marbles in a bag we pull out one marble which may be blue or red .

Now there are 5 marbles left in the bag .Now what is the probability that second marble is red ?

It depends . If the first marble was red .Then the bag is left with 2 red marble out of 5 .So probability of drawing a red marble on the second draw is 2/5 .

Now if the first marble pull out of the draw is blue then there are 3 red marbles in the bags and probability of pulling a red marble on the second draw is 3/5.

The second draw is a dependent event and it depends on the what happened in the first draw .