A sample of 12 joint specimens of a particular type gave a sample mean proportional limit stress of 8.55 MPa and a sample standard deviation of 0.76 MPa. (a) Calculate and interpret a 95% lower confidence bound for the true average proportional limit stress of all such joints. (Round your answer to two decimal places.) MPa

95% of the lower confidence interval for the true average proportional limit stress of all such joints

7.7829

95% of the confidence interval for the true average proportional limit stress of all such joints

(7.7829, 9.3171)

Step-by-step explanation:

Step(i):-

Given that the sample size 'n' = 12

Mean of the sample = 8.55

The standard deviation of the sample (S) = 0.76

Step(ii):-

95% of the confidence interval is determined by

Degrees of freedom = n-1 = 12-1 = 11

t₀.₀₂₅ = 3.4966

(8.55 - 0.7671 , 8.55+0.7671)

(7.7829, 9.3171)

Final -

95% of the confidence interval for the true average proportional limit stress of all such joints

(7.7829, 9.3171)

maximum area = xy = (16)(32) = 512 ft2

to maximize the area of the garden, the side of the fence parallel to the side of the house should be 32 ft long, and the other two sides should both have length 16 ft.'

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