00:01
For the first question, i'll note that we do need to assume fairness in order to actually meaningfully answer this question.
00:11
If it's a biased coin, then we would need more information in order to actually describe the probability distribution.
00:18
But we'd have that if we assume fairness, probability that a tail occurs, probability that a head occurs must both be must both be equal to each other.
00:30
And since there are only two possible outcomes, that means that they must both be 1 over 2, or 0 .5.
00:37
For the second question, let's see here, we are just constructing the probability distribution from the given information.
00:57
So we are told that 22 % of the families in this particular state have no children.
01:04
So probability that x equals 0 would be 0 .22.
01:08
Probability that they have one child, well we're told that 20 % have one child, so it's 0 .2.
01:19
We're told that 25 % have two children, so probability that x equals 2 is 0 .25.
01:26
And probability that they have three children is 33%.
01:31
So probability that x equals 3 is simply 0 .33.
01:37
Then for part a, or pardon me, for the third listed question, we can consider the number of left -handed students in the sample as a binomial random variable, where the number of trials is equal to 29, and the probability of success, a person being left -handed, is 0 .18 or 18%...