The time that a technician requires to perform preventative maintenance on an air-conditioning unit has a mean time of 1 hour and a standard deviation of 1 hour. Your company operates 70 of these units (n = 70). Use the Central Limit Theorem to estimate the following. Mean of the sample mean time = hour. Standard deviation of the sample = hours. The zscore associated with 50 minutes (0.83 hours) is The probability that the average maintenance time exceeds 50 minutes (P E > 0.83) is