Researchers at theMayo Clinichave studied the effect of sound levels on patient healing and have found a significant association (louder hospital ambient sound level is associated with slower postsurgical healing). Based on the Mayo Clinic's experience, Ardmore Hospital installed a new vinyl flooring that is supposed to reduce the mean sound level (decibels) in the hospital corridors. The sound level is measured at five randomly selected times in the main corridor.

New FlooringOld Flooring42484151404437484452

Click here for the Excel Data File

(a-1)

Does the evidence convince you that the mean sound level has been reduced? Select the appropriate hypotheses.

a.H₀:₁-₂ 0 vsH₁:₁-₂> 0b.H₀:₁-₂ 0 vsH₁:₁-₂< 0ab

(a-2)At= .05, what is the decision rule? Assume unequal variances. Use the quick rule for degrees of freedom.

a. Reject the null hypothesis ift_calc< -1.86 (8 df.)b. Reject the null hypothesis ift_calc> -1.86 (8 df.)ab

(a-3)

Calculate the test statistic.(Round your answer to 4 decimal places. Input the answer as a positive value.)

Test statistic

(a-4)At= .05, is the mean sound level reduced?

(Click to select)

Reject

Do not reject

H₀, the mean is(Click to select)

greater

smaller

not changed

.

(b-1)

At =.05, has the variance changed? Choose the correct hypothesis.

a.H₀:₁²/₂² 1vs.H₁:₁²/₂²= 1b.H₀:₁²/₂²= 1vs.H₁:₁²/₂² 1ab

(b-2)At= .05, what is the decision rule?a. RejectH₀ifF_calc< 9.6 orF_calc> .1042.b. RejectH₀ifF_calc> 9.6 orF_calc< .1042ab

(b-3)What is the test statistic?(Round your answer to 2 decimal places.)

Test statistic

(b-4)At = .05, is the variance changed?

(Click to select)

Reject

Do not reject

H₀, the variance is(Click to select)

greater

smaller

not changed

.