Answer: If P(x<a) = 0.6, then the value of a will be 0.25.
In this type of problem, it is safe to assume the normal distribution unless you are told something different.
In this probability, we have to find the z-score for a that gives a probability of 0.6. You will need a normal distribution chart to do this problem. Just find the probability that is closest to 0.6 and use that z-score.
First you multiply the two equations, equaling 3000000 kg and 60000 kg respectively. Once you have those numbers, you divide the Oakland mass by the Mapleville mass, so 3000000/60000. The answer is 50, to the tree is B, 50 times as big.
Answer:
they are directly proportional
so
5/22*7=1.59
he would finish in 1.59 min