In: Statistics and Probability
A ski gondola carries skiers to the top of a mountain. Assume that weights of skiers are normally distributed with a mean of 184lb and a standard deviation of 42lb. The gondola has a stated capacity of 25 passengers, and the gondola is rated for a load limit of 3500 lb. Complete parts (a) through (d) below.
a) Given that the gondola is rated for a load limit of 3500lb, what is the maximum mean weight of the passengers if the gondola is filled to the stated capacity of 25 passengers?
The maximum mean weight is
b) If the gondola is filled with 25 randomly selected skiers, what is the probability that their mean weight exceeds the value from part (a)?
The probability is
c) If the weight assumptions were revised so that the new capacity became 20 passengers and the gondola is filled with 20 randomly selected skiers, what is the probability that their mean weight exceeds 175lb, which is the maximum mean weight that does not cause the total load to exceed 3500lb? The probability is
d) Circle the right choices
Since the probability of overloading is over 50%/or under 5% the new capacity does/does not appear safe enough
Solution:
a) Given that the gondola is rated for a load limit of 3500lb, what is the maximum mean weight of the passengers if the gondola is filled to the stated capacity of 25 passengers?
Answer: The maximum mean weight is:
b) If the gondola is filled with 25 randomly selected skiers, what is the probability that their mean weight exceeds the value from part (a)?
Answer: We have to find
Using the z-score formula, we have:
Now using the standard normal table, we have:
Therefore, the probability is 0.8531
c) If the weight assumptions were revised so that the new capacity became 20 passengers and the gondola is filled with 20 randomly selected skiers, what is the probability that their mean weight exceeds 175lb, which is the maximum mean weight that does not cause the total load to exceed 3500lb?
Answer: We have to find
Using the z-score formula, we have:
Now using the standard normal table, we have:
Therefore, the probability is 0.5832
d) Circle the right choices
Since the probability of overloading is over 50% the new capacity does not appear safe enough