Total coins = 10 ( 4 + 3 + 3 = 10).
The probability of picking a nickel first = 4/10 = 2/5 ( 4 nickels out of 10 total).
The probability of picking a dime second = 3/9 = 1/3 ( 3 dimes out of 9 coins left).
The probability of picking the third coin as a quarter = 3/8 ( 3 quarters out of 8 coins left).
The probability of picking all three in that order = 2/5 x 1/3 x 3/8 = 1/20
A. It is an experiment as the sales director is applying treatment ( the training ) to a group and recording the results.
B. I would have 250 sales representatives from each region take the training and 250 from each region to not take it so i can be able to see if it affects both regions differently. The representatives from each region would be chosen at random and the length of their training would be the same for all.
C. now you would only be able to have 200 people from each region train. this would lower the percentage of the impact the training had on the amount of sales ( if any) . For example, if the original 250 trained people in a region increased the sales in that region by 20 percent and 50 of those people ended up not actually training, the sales would have only increased by 16 percent.
D. correlational research is best to establish causality. for example, the amount of training the representatives got may affect how much they are able to sell. also the number of representatives trained may affect the amount sold
