Question

The slant shear test is widely accepted for evaluating the bond of resinous repair materials to concrete; it utilizes cylinder specimens made of two identical halves bonded at 30°. An article reported that for 11 specimens prepared using wire-brushing, the sample mean shear strength (N/mm2) and sample standard deviation were 18.10 and 1.56, respectively, whereas for 11 hand-chiseled specimens, the corresponding values were 22.18 and 4.02. Does the true average strength appear to be different for the two methods of surface preparation? State and test the relevant hypotheses using a signific

Answer 1

@agent0smith

Answer 2

let me finish putting the rest of the question up. I have a solution as well wtih all my work. There is a part I am having a difficult time answering.

Answer 3

State the rejection region(s). (If the critical region is one-sided, enter NONE for the unused region. Round your answers to three decimal places.)

Answer 4

Compute the test statistic value. (Round your answer to three decimal places.)

Answer 5

Reject H0. The data suggests that the true average strength is different for the two methods of surface preparation.
Fail to reject H0. The data suggests that the true average strength is not different for the two methods of surface preparation.
Reject H0. The data suggests that the true average strength is not different for the two methods of surface preparation.
Fail to reject H0. The data suggests that the true average strength is not different for the two methods of surface preparation.

Answer 6

It is assumed that means of distributions for both preparation types are equal.
It is assumed that distributions for both preparation types are the same.
It is assumed that distributions for both preparation types are normal.
It is assumed that variances of distributions for both preparation types are equal.

Answer 7

I got the rejection regions figured out.

t<=-2.179
t>=2.179

The test statistic I got was
t=-3.138

We are too
Reject H0. The data suggests that the true average strength is different for the two methods of surface preparation.

I am having a hard time figuring out the last question

Answer 8

@dumbcow