Probability and stats

Question

The probability of rolling any number on a weighted 6-sided die, with faces numbered 1 through 6, is directly proportional to the number rolled. What is the poro ability of getting 5 if the die is rolled only once? 

I don't understand the proportional part. Could someone please explain and solve this for me? 

Answer 1

Nice explanation Marlene!  Weighted dice don't act like normal dice so the probability of getting any one particular outcome won't be the same for each side in a single toss (or any other tosses).  Make sure you aren't playing with weighted dice when doing actual games of chance! : )

Answer 2

Hi Sarika,

 

If the probability of rolling a particular # is related to that number, then

in 21 rolls, you'll have the following roll a "1" once, a "2" twice, a "3" thrice, etc

 

Then the probability of those number is

 

P(1) = 1/21

P(2) = 2/21

P(3) = 3/21

P(4) = 4/21

P(5) = 5/21

P(6) = 6/21

 

Notice the denominator is 21 because 1+2+3+4+5+6 = 21

 

The probability of getting a 5 if the die is rolled only once is 5/21.