Answer:
a) 0.5 = 50% of flanges exceed 1 millimeter.
b) A thickness of 0.96 millimeters is exceeded by 90% of the flanges
Step-by-step explanation:
A distribution is called uniform if each outcome has the same probability of happening.
The uniform distributon has two bounds, a and b, and the probability of finding a value higher than x is given by:

The thickness of a flange on an aircraft component is uniformly distributed between 0.95 and 1.05 millimeters.
This means that 
(a) Determine the proportion of flanges that exceeds 1.00 millimeters.

0.5 = 50% of flanges exceed 1 millimeter.
(b) What thickness is exceeded by 90% of the flanges?
This is x for which:

So




A thickness of 0.96 millimeters is exceeded by 90% of the flanges