Cedex wants to compare the performance of two manufacturing methods: Method 1, in which products are grouped into families, and Method 2, in which production equipment is grouped into families. The number of units manufactured using either manufacturing method follows a normal distribution. The number of units manufactured using method 1 was observed for 120 randomly selected days and the number of units manufactured using method 2 was observed for 150 days.

Let X1 be the number of units manufactured on day i using method 1, and X2 the number of units manufactured on day i using method 2. The means and variances obtained for each method are presented below.

Sample 1 : n1=120 / x1= 69 , s quare 1 = 144

Sample 2 : n2=150 / x2=72.3 / s square 2= 169

A hypothesis test on two means was performed, at the significance level oc = 0.05. The hypothesis tested was that the average number of units produced per day with method 1 is identical to the average number of units produced per day with method 2.

Which statement is true for this test?

The reduced deviation Z (Zcai) for this test is -2.163 and we do not reject Ho, so there is a significant difference between the two manufacturing methods.

0 The Z-reduced deviation (Zcal) for this test is -0.173 and we reject Ho, so there is not a significant difference between the two manufacturing methods.

CD The reduced deviation Z (Zcai) for this test is -2.163 and we reject Ho, so there is a significant difference between the two manufacturing methods.

0 The Z-reduced deviation (Zcai) for this test is -0.173 and we do not reject Ho, so there is not a significant difference between the two manufacturing methods.

The Z-reduced deviation (Zcal) for this test is -0.173 and we reject Ho, so there is a significant difference between the two manufacturing methods.

The Z-reduced deviation (Zcai) for this test is -0.173 and we do not reject Ho, so there is a significant difference between the two manufacturing methods.

The Z-reduced deviation (Zcai) for this test is -2.163 and we do not reject Ho, so there is not a significant difference between the two manufacturing methods.

The Z-reduced deviation (Zcal) for this test is -2.163 and we reject Ho, so there is no significant difference between the two manufacturing methods.