Two additives to Portland cement are being tested for their effect on the strength of concrete. 21..

Two additives to Portland cement are being tested for their
effect on the strength of concrete. 21 batches were made with Additive A, and
their strengths showed standard deviation sA = 41.3. 16 batches were
made with the same percentage of Additive B, and their strengths showed
standard deviation sB = 26.2. Assume that the strengths of concrete
follow a normal distribution. Is there evidence at the 1% level of significance
that the concrete made with Additive A is more variable than concrete made with
Additive B?

Don't use plagiarized sources. Get Your Custom Essay on
Two additives to Portland cement are being tested for their effect on the strength of concrete. 21..
Just from $13/Page
Order Essay