Practice test 1
I have a question that I can't just seem to figure out. It goes like this.
#23
It is known that 20% of the population of smallville has blue eyes. If four people are chosen at random from
this population, what is the proability that at least one of the four has blue eyes?
I know you can use the at least one rule, and basically substract from non-blue eye, which is 1-(4/5)^4
But I actually want to know how to calculate the four people with blue eyes, and what are their probability.
I know you need to find out one person with blue eye's probability and two people with blue and and three and
four and add them all up.
But, How can you find that? How can you calculate the probability of those each?
I never had stats, and always been weak at Math.
Any help will be appreciated. Thanks.
I have a question that I can't just seem to figure out. It goes like this.
#23
It is known that 20% of the population of smallville has blue eyes. If four people are chosen at random from
this population, what is the proability that at least one of the four has blue eyes?
I know you can use the at least one rule, and basically substract from non-blue eye, which is 1-(4/5)^4
But I actually want to know how to calculate the four people with blue eyes, and what are their probability.
I know you need to find out one person with blue eye's probability and two people with blue and and three and
four and add them all up.
But, How can you find that? How can you calculate the probability of those each?
I never had stats, and always been weak at Math.
Any help will be appreciated. Thanks.
