Question

In a population, 93% of the people are right-handed, and 7% of the people are left-handed. In each of the last 100 days, 1 person in the population has been randomly stopped on the street, For the first 93 days, the person stopped was right-handed, and for the last 7 days, the person stopped was left-handed.

If the same person is allowed to be stopped on more than 1 day, what is the probability that the next person stopped will be right-handed?

Answer 1

@Yttrium

Answer 2

There is an equal probability each day, since it is an independent event. Like if I were to flip a coin, knowing that my last 2, 20, or 2000 flips were heads does not change the likelihood that my next flip will be heads.

Answer 3

@BTaylor so the probability is still 93%?

Answer 4

Yes. Good job!

Answer 5

Morgan is playing a board game that requires three standard dice to be thrown at one time. Each die has six sides, with one of the numbers 1 through 6 on each side. She has one throw of the dice left, and she needs a 17 to win the game. What is the probability that Morgan wins the game (order matters)? @BTaylor

Answer 6

The only combination of numbers to make 17 is 5+6+6 right ?

Answer 7

You can get a sum of 17 with a 6, a 6, and a 5. With different arrangements, there are 3 ways you could throw a 17. (5,6,6 6,5,6 6,6,5)
There are \(6^3 = 216\) possibilities for the last throw.
Can you turn this into a probability?

Answer 8

1/6 ?

Answer 9

noo , that can't be right because thats not one of my choices.

Answer 10

1/216 ?

Answer 11

it would be 3/216 because that is the number of target ways (to achieve 17) divided by the number of possible ways (216).
Simplifying, it would be 1/72. Is that an answer choice?

Answer 12

yes .

Answer 13

Mary Katherine has a bag of 3 red apples, 5 yellow apples and 4 green apples. Mary takes a red apple out of the bag and does not replace it. What is the probability that the next apple she takes out is yellow?

Answer 14

is that 5/11 ?

Answer 15

yep!

Answer 16

A quality inspector at a valve manufacturer randomly selects one valve from each batch of fifty valves to inspect for noncompliance. The first batch of fifty valves has five non-compliant ones. The second batch of fifty valves has four non-compliant valves.

Find the probability that the inspector selects a non-compliant valve both times.

Answer 17

can you help with that one ?

Answer 18

P(first one AND second one) = P(first one) x P(second one)
What is the probability each time?
Multiply those (since they're independent, you can do that) and that is the probability that both are.

Answer 19

I thought it would be 20/100 or 2/10 or 1/5 but none of those are a choice.

Answer 20

you have: \[\frac{5}{50} \times \frac{4}{50} = \frac{1}{10} \times \frac{2}{25} = \frac{2}{250} = \frac{1}{125}\]
I think you added the denominator instead of multiplying.

Answer 21

Awhh man , you beat me to it I was just about to say that I got 1/125 the second time I did it .

Answer 22

haha but you got it. I think you get it now!

Answer 23

If events A and B are DEPENDENT, then

A)
A and B must occur together.
B)
A and B cannot occur together.
C)
A's occurrence can affect the probability of B's occurrence.
D)
A's occurrence cannot affect the probability of B's occurrence.

*** C is correct right ? or A ?

Answer 24

C is correct.