Question

Refer to the Lincolnville School District bus data. In the maintenance cost variable, the mean maintenance cost for last year is $4,552 with a standard deviation of $2,332. Estimate the number of buses with a maintenance cost of more than $6,000. Note: Round intermediate calculations to 2 decimal places and final answer to the nearest whole number.

Answer 1

To estimate the number of buses with a maintenance cost of more than $6,000, we can use z-scores and the standard normal distribution.

Step-by-step explanation:

To estimate the number of buses with a maintenance cost of more than $6,000, we need to use the concept of z-scores and the standard normal distribution. We can calculate the z-score using the formula:

z = (x - mean) / standard deviation

Substituting the values given:

z = (6000 - 4552) / 2332 = 0.662

Now, we need to find the area under the standard normal curve to the right of the z-score. This area represents the proportion of values greater than $6,000. Using a standard normal table or a calculator, we find that the area is approximately 0.254. Multiplying this proportion by the total number of buses will give us the estimated number of buses with a maintenance cost of more than $6,000.