Discussion:
Q: A company making plastic opitical components for bar code scanners was studying inconsistencies in an optical measurement called tilt. The company knew that scanners work best when tilt measurement is small. Two different types of locking mechanisms used in the mold produced the following units.
Taper Locks Locking Pins
X= 1.262 0.561
S 0.297 0.307
n 20 20
a Assuming that the population variances are equal and the populations are normally distributed, at the 0.05 level of significance is there evidence of a difference in the means between taper locks and locking pins.
b. Repeat (a) assuming that the population variances are not equal.
c. compare the results of a and b