Answer:
29.49% probability that a production time is between 9.7 and 12 minutes
Step-by-step explanation:
An uniform probability is a case of probability in which each outcome is equally as likely.
For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.
The probability that we find a value X between c and d, in which d is greater than c, is given by the following formula.

Production times are evenly distributed between 8 and 15.8 minutes and production times are never outside of this interval.
This means that 
What is the probability that a production time is between 9.7 and 12 minutes?
.
So


29.49% probability that a production time is between 9.7 and 12 minutes