1. a bag contains the letters of the word “probability”. if two tiles are chosen (with replacement) what is the probability of choosing an “o” and a “b”?

Since "PROBABILITY" has 11 letters in it, then every letter has 1/11 chances of getting picked, so the chances of getting an O tile would be 1/11, same for getting a B tile. But if you were to get both of them consecutively, then the chances would be 1/11 of 1/11 because you have 1/11 of a chance to get and O and then 1/11 of a chance to get a B. So you would be looking for 1/11 of 1/11, which means multiplying the divisor, 11*11=121. Therefore, you should have 1/121 chance of getting an O and B tile.

the median here is 25. your lowest value is 14 and highest value is 48. to find the third quartile, find the medium number in between 25 and 48 which would be 42 i believe.