Answer: 0.0368
Explanation:
The cumulative distribution function for exponential distribution is :-

, where
is the mean of the distribution.
Given : The time to process each item is exponentially distributed with a mean of 1 minute .
In hour, the mean time to process each item =
hour
Then , the probability that the worker finishes in less than 2.25 hours :-

Hence, the probability that the worker finishes in less than 2.25 hours = 0.0368