The mean length of a small counter balance bar is 43 millimeters. There is concern that the adjustments of the machine producing the bars have changed. Test the claim at the 0.02 level that there has been no change in the mean length. The alternate hypothesis is that there has been a change. Twelve bars (n = 12) were selected at random and their lengths recorded. The lengths are (in millimeters) 42, 39, 42, 45, 43, 40, 39, 41, 40, 42, 43 and 42. Has there been a statistically significant change in the mean length of the bars?
a. What is Ho: _______________________
A) µ = 43
B) µ < 43
C) π = 43
D) µ ≠ 43
b. What is H1:________________________
A) µ = 43
B) µ < 43
C) π = 43
D) µ ≠ 43
c. What is the value of p:_________________________
A) .028
B) .014
C) .14
D) 2.91
c. What is the decision
A) Do not reject Ho
B) Reject Ho
d. What is the conclusion
A) There has been a significant change in the mean length of the bars
B) There has been no change in the mean length of the bars