Rolling a pair of dice 20 times

So you should divide each frequency by 20 instead of 36.In summary, the conversation discusses creating a frequency table for the outcome of rolling two dice 20 times. The results are listed and there is a question about why the frequencies do not add up to 100%. It is clarified that the frequencies should be divided by 20 instead of 36 since the dice were only rolled 20 times.
  • #1
Science4ver
35
0

Homework Statement



I have math experiment where I roll a pair of honest dice 20 times.

The results are:

2,3,4,4,5,5,6,6,6,7,7,7,7,7,9,9,9,10,10,11

write a frequency table of the outcome of the dice roll with respect to size:

2,3,4,5,6,7,8,9,10,11,12

Firstly there must 36 possible outcomes since there two dice with 6 sides.

This gives me a frequency table which looks as follows:

x P(x)

2 1/36

3 1/36

4 2/36

5 2/36

6 3/36

7 5/36

8 0

9 3/36

10 2/36

11 1/36

12 0

Is this correct? By why doesn't the frequencies add up to 100%?? Is it because I only role the dice 20 times?
 
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  • #2
Science4ver said:

Homework Statement



I have math experiment where I roll a pair of honest dice 20 times.

The results are:

2,3,4,4,5,5,6,6,6,7,7,7,7,7,9,9,9,10,10,11

write a frequency table of the outcome of the dice roll with respect to size:

2,3,4,5,6,7,8,9,10,11,12

Firstly there must 36 possible outcomes since there two dice with 6 sides.

This gives me a frequency table which looks as follows:

x P(x)

2 1/36

3 1/36

4 2/36

5 2/36

6 3/36

7 5/36

8 0

9 3/36

10 2/36

11 1/36

12 0

Is this correct? By why doesn't the frequencies add up to 100%?? Is it because I only role the dice 20 times?

Dividing by 36 would be correct if you rolled the dice 36 times---but you didn't.
 
  • #3
Ray Vickson said:
Dividing by 36 would be correct if you rolled the dice 36 times---but you didn't.

So I just exchange 36 with 20?
 
  • #4
Science4ver said:
So I just exchange 36 with 20?

What do YOU think?
 
  • #5
Ray Vickson said:
What do YOU think?

yes because I roll the dice 20 times and not 36.
 
  • #6
Science4ver said:
yes because I roll the dice 20 times and not 36.

Right!
 

FAQ: Rolling a pair of dice 20 times

1. How many possible outcomes are there when rolling a pair of dice 20 times?

There are 129,600 possible outcomes when rolling a pair of dice 20 times.

2. What is the probability of rolling a double six in 20 rolls?

The probability of rolling a double six in 20 rolls is approximately 0.0003 or 0.03%.

3. What is the expected value of rolling a pair of dice 20 times?

The expected value of rolling a pair of dice 20 times is 140. This means that if the experiment is repeated many times, the average of the resulting values will converge to 140.

4. Is rolling a pair of dice 20 times considered a random experiment?

Yes, rolling a pair of dice 20 times is considered a random experiment because the outcome of each roll is not dependent on the previous rolls and is determined by chance.

5. How does the probability of rolling a seven change after each roll?

The probability of rolling a seven does not change after each roll. Each roll of the dice is an independent event, so the probability of rolling a seven remains constant at approximately 0.167 or 16.7%.

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