Final answer:
The longest 25 percent of repair times require at least 3.375 hours, and this figure represents the 75th percentile for maintenance tasks. For the air conditioner preventive maintenance, the average time planned per technician is 1.1 hours.
Step-by-step explanation:
The question regarding what percentage of time is allocated to corrective maintenance pertains to the interpretation of statistical data related to maintenance activities. Based on provided data, the longest 25 percent of repair times take at least 3.375 hours, which corresponds to the 75th percentile of furnace repair times. This means that the top 25 percent of time-consuming repairs require at least 3.375 hours to complete. Looking at the uniform distribution between 1.5 and 4 hours with an area of 0.25 shaded to the right, it represents the longest 25 percent of repair times.
In the context of air conditioner preventive maintenance, the company averages one hour per service with a standard deviation of one hour. They anticipate servicing a sample of 70 units and plan to allocate an average of 1.1 hours per technician. To determine if this is sufficient, we need to calculate whether 1.1 hours fall within an acceptable range of the normal distribution defined by the mean and standard deviation. However, the question concerning how much time is allocated specifically to corrective maintenance is not directly answered with the provided data.