Question

Does the probability of rolling a sum of 2 appear to be the same as the probability of rolling a sum of 7? Explain your answer.

Answer 1

Empirical or theoretical probability?

Answer 2

I have seen your question yesterday and If I remember correctly the question was referring to empirical probability
It was basically based on your observations

Answer 3

You had to roll the die 60 times and then record the amount of times it landed on each number

Answer 4

yes but this question is different im having trouble with probablity

Answer 5

ok well then lets pretend or assume that this is theoretical probability

Ok when you roll a die once there are a total of 6 diff options - it can land on any of 6 number. It can land on 1 , 2, 3, 4, 5, and 6

The probability that it will land on 1 is ...
\[ \text{ Probability of 2} = \frac{\text{ How many times it lands on 2}}{\text{ Total # of outcomes}}\]

Now lets look above ... How many outcomes are there???
6 . It can land on 6 numbers ... 1,2,3,4,5 and 6

How many times does it land on a 2???
Only once so 1

Therefore the probability that it will land on 2 is
\[ \text{ Probability of 2} = \frac{\text{ 1}}{\text{ 6}}\]

Answer 6

Oh whoopppsssss
Didnt read the question ... it asks for sum of 2 and sum of 7

Answer 7

ok this all depends on how many times you roll a die

Answer 8

Is there more to the question?

Answer 9

well i have more questions

Answer 10

ya but is there a first part to the question?

Answer 11

Like im assuming that you havta roll the die twice

Answer 12

so for example there is not a single answer? your answer will be differfent then mine depending on how many times i roll the dice?

Answer 13

no thats the whole question

Answer 14

Not really ... thats only in empirical probability

Answer 15

In theoretical probability its always the same its always a 1/6 that you will land on a 2

Answer 16

ok so lets see when you roll the die twice
The only way you can get a sum of 2 is if you roll a 1 on the first time and a 1 on the second time you roll the die
1+1=2

Answer 17

So the probability that you will get a 1 is a 1/6
so (1/6)*(1/6)=1/36
The probability that you will roll on 1 twice in a row is 1/36

Answer 18

for a sum of 7 you can need to roll on a 3 and 4 so its 3+4=7
Now there are 2 ways to get a sum of 7 and I will show you below

Option#1
Roll #1 we get 3
Roll #2 we get 4

Probability that will land on 3 is a 1/6
Probability that will land on 4 is a 1/6
So probability that will first land on 3 and then 4 is (1/6)*(1/6)=1/36

Option#2
Roll #1 we get 4
Roll #2 we get 3

Probability that we will land on 4 is 1/36
Probability that will land on 3 is 1/6
Probability that will land on both is (1/6)(1/6)=1/36

The probability that we will get either option 1 or option 2 is (1/36)+(1/36)=2/36

So therefore the probability that will get a sum of 7 is 2/36

Answer 19

So does the probability appear to be the same?????

Answer 20

Ok i dont think i explained this clearly ...

Answer 21

yes

Answer 22

hmmm i gotta go study but maybe @freckles would like to help :P

Answer 23

So how many dice do you have? 2,3,4,5? I assumed it was more than 1 since you said sum of the die.

Answer 24

If it is 2 die:

This picture represents all the possible outcomes of rolling two fair die together