If each brick is within 1/8 inches of 8 inches, then that's an error of
[tex] \frac{(\frac{1}{8})}{8} =\frac{1}{64}[/tex]
If we then take the total length if each brick is 8 inches,
[tex]100*8=800[/tex]
Then take 1/64 of this
[tex]800*\frac{1}{64}=12.5[tex]
So the upper and lower bounds are 12.5 inches either side of 800 inches
787.5, and 812.5
So we can say that
[tex]787.5 \leq x \leq 812.5[/tex]
Which would be the answer to part a. parts b and c would be the lower and upper bounds, so 787.5 and 812.5 respectively
Hope this helps
