30 points
there are four sixth graders and seven seventh graders in elsa's chess club. two members of the club will be chosen at random to attend a tournament between several other chess clubs. elsa is using simulation to determine the experimental probability of randomly selecting two sixth graders. so, she places four red discs (to represent the sixth graders) and seven blue discs (to represent the seventh graders) in a bag. she randomly selects one disc from the bag, records the color, keeps the disc out, selects another disc and records it, and then returns both discs to the bag. elsa does this twenty-five times. her results are shown in the table below.

b, b b, r b, r b, b r, b
b, r b, b b, r b, r r, b
r, b r, r b, r r, b b, r
b, b r, r b, r r, r r, b
b, b r, r b, b r, r b, r
based on elsa's results, what is the experimental probability of two sixth graders being randomly selected? express your answer as a percent, rounded to the nearest whole number.
a0%

Hmm. I'm not the best at math, but I've found that:

The probability of ONE sixth grader being chosen out of each bag was:

1st Bag: 30%
2nd Bag: 40%
3rd Bag: 60%
4th Bag: 60%
5th Bag: 50%

So, I multiplied the probability by itself to find the probability of two things happening at the same time, the probability of TWO sixth graders being chosen: 

1st Bag: 30% * 30% = 9%
2nd Bag: 40% * 40% = 16%
3rd Bag: 60% * 60% = 36%
4th Bag: 60% * 60% = 36%
5th Bag: 50% * 50% = 25%

So, I found the Proability of TWO sixth graders being chosen at the same time, but now I have to find the experimental probability of it based on the information given.

I found this difficult to do, because I myself haven't learned it yet.

So I averaged out all 5 bags and found that:

The Average experimental probability of TWO sixth graders being chosen randomly from the same bag with 4 Sixth Graders and 7 Seventh Graders in it, with experimental data 

is: 24.4%

Here's an Example: https://math.stackexchange.com/questions/293668/whats-the-probability-if-getting-the-same-objects-of...

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.