1. Manama cement factory produces precast cement blocks, last year's record showed the mean weight per block as 95 KG. This year they have sampled 50 units, and the average weight per block was 98 KG,...

Extracted text: 1. Manama cement factory produces precast cement blocks, last year's record showed the mean weight per block as 95 KG. This year they have sampled 50 units, and the average weight per block was 98 KG, with a variance of 6 KG. calculate the z value associated with this sample? (ans: 1.22 + or – 0.09)