Question Details
Problem we have equal population standard deviations. Two different processes for producing
ball bearings. The diameters must be as colse to the industry standard. chart below. Process A
Process B
Mean 0.002 mm 0.0026 mm Sample size 12 14
Standard deviation 0.0001 mm 0.00012 mm
If the calulated vlue of t is+2.70 what woudl be the decison using the 0.01 level of signifcance
a. reject null and conclude the means are different
b. reject and conclude the means are the same
c. fail to reject null and conclude the means are the same
d. fail to reject null and conclude the means are different
Solution
c) Critical value is 2.797 and 2.70 is less than that.