Answer:
we say for  μ = 50.00 mm we be 95% confident that machine calibrated properly with ( 49.926757  ,  50.033243 ) 
Step-by-step explanation:
Given data 
n=29
mean of x = 49.98 mm
S = 0.14 mm
μ = 50.00 mm
Cl = 95%
to find out 
Can we be 95% confident that machine calibrated properly
solution
we know from t table 
t at 95% and n -1 = 29-1 = 28 is  2.048
so now 
Now for  95% CI for mean is
(x - 2.048 × S/√n  ,  x + 2.048 × S/√n )
(49.98 - 2.048 × 0.14/√29  ,  49.98 + 2.048 × 0.14/√29 )
( 49.926757  ,  50.033243 ) 
hence we say for  μ = 50.00 mm we be 95% confident that machine calibrated properly with ( 49.926757  ,  50.033243 )