Assume that the mean hourly cost to operate a commercial airplane follows the normal distribution with a mean of $2,225 per hour and a standard deviation of $220.
What is the operating cost for the lowest 5 percent of the airplanes?
4 answers
According to the standard bell curve and the empirical rule, the lowest 5% would be 2 standard deviations below the mean making the operating cost of the lowest 5% of airplanes equal to $1785
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z score related to that proportion.
For the lowest 5%, you need a Z score of -1.645.
Insert the values in the above equation to solve for the score.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z score related to that proportion.
For the lowest 5%, you need a Z score of -1.645.
Insert the values in the above equation to solve for the score.
.59
Assume that the hourly cost to operate a commercial airplane follows the normal distribution with a mean of $5,018 per hour and a standard deviation of $493.
What is the operating cost for the lowest 1% of the airplanes? (Round z value to 2 decimal places and round final answer to nearest whole dollar.)
Operating cost
What is the operating cost for the lowest 1% of the airplanes? (Round z value to 2 decimal places and round final answer to nearest whole dollar.)
Operating cost
2 answers