Question

QUESTION 17 A company produces concrete blocks for use in building retaining walls. A customer requires that the average compressive strength of the blocks be greater than 2000 psi. A random sample of 15 blocks are tested, and the sample average is calculated as 2093 psi with a standard deviation of 197 psi. The customer believes that a different supplier can provide them with a stronger product, so they sample 15 blocks from this new supplier which yields a sample average of 2236 psi and a standard deviation of 375 psi. If they wish to test whether the mean strength of the blocks for each supplier are equal to one another, it will be a t-test with what degrees of freedom? A 21 B. 26 C.28 O D.

Answer 1

Dates s, 19チ X2- -2236 deg γ e e of freedom (df)-Pitha-2-