Concept explainers
The article “Slender High-Strength RC Columns Under Eccentric Compression” (Magazine of Concrete Res., 2005: 361–370) gave the accompanying data on cylinder strength (MPa) for various types of columns cured under both moist conditions and laboratory drying conditions.
Type | ||||||
1 | 2 | 3 | 4 | 5 | 6 | |
M: | 82.6 | 87.1 | 89.5 | 88.8 | 94.3 | 80.0 |
LD: | 86.9 | 87.3 | 92.0 | 89.3 | 91.4 | 85.9 |
7 | 8 | 9 | 10 | 11 | 12 | |
M: | 86.7 | 92.5 | 97.8 | 90.4 | 94.6 | 91.6 |
LD: | 89.4 | 91.8 | 94.3 | 92.0 | 93.1 | 91.3 |
a. Estimate the difference in true average strength under the two drying conditions in a way that conveys information about reliability and precision, and interpret the estimate. What does the estimate suggest about how true average strength under moist drying conditions compares to that under laboratory drying conditions?
b. Check the plausibility of any assumptions that underlie your analysis of (a).
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Chapter 9 Solutions
Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
- A study of the properties of metal plate-connected trusses used for roof support yielded the following observations on axial stiffness index (kips/in.) for plate lengths 4, 6, 8, 10, and 12 in: 4: 321.2 409.5 311.0 326.5 316.8 349.8 309.7 6: 439.1 347.2 361.0 404.5 331.0 348.9 381.7 8: 390.4 366.2 351.0 357.1 409.9 367.3 382.0 10: 362.7 452.9 461.4 433.1 410.6 384.2 362.6 12: 402.4 441.8 419.9 410.7 473.4 441.2 465.8 USE SALT Does variation in plate length have any effect on true average axial stiffness? State the relevant hypotheses using analysis of variance. ○ Ho: H₁ = H₂ = H3 = H4=H5 Ha: all five u's are unequal O Ho: H₁ H₂ H3 H4 H5 Ha: all five μ's are equal Ho H₁ = ₂ = 3 = H4 = 5 H₂: at least two μ's are unequal Ho: H₁ H₂ H3 H4 H5 Ha: at least two μ's are equal Test the relevant hypotheses using analysis of variance with a = 0.01. Display your results in an ANOVA table. (Round your answers to two decimal places.) Mean Degrees of Sum of freedom Squares Squares Source Treatments…arrow_forwardA study of the properties of metal plate-connected trusses used for roof support yielded the following observations on axial stiffness index (kips/in.) for plate lengths 4, 6, 8, 10, and 12 in: 4: 333.2 409.5 311.0 326.5 316.8 349.8 309.7 6: 433.1 347.2 361.0 404.5 331.0 348.9 381.7 8: 382.4 366.2 351.0 357.1 409.9 367.3 382.0 10: 350.7 452.9 461.4 433.1 410.6 384.2 362.6 12: 413.4 441.8 419.9 410.7 473.4 441.2 465.8 LUSE SALT Does variation in plate length have any effect on true average axial stiffness? State the relevant hypotheses using analysis of variance. O Hoi Hy #fly #Hz" Ha #Hs H: all five μ's are equal O Hoi H₂H₂ = H3 = HaHs H: at least two μ's are unequal O Hoi H₂ = H₂ = H₂ "HaHs H: all five μ's are unequal O Hoi H₂ #4₂ # Hz*H4 *H5 H: at least two μ's are equal Test the relevant hypotheses using analysis of variance with a = 0.01. Display your results in an ANOVA table. (Round your answers to two decimal places.) Degrees of Sum of Mean freedom Squares Squares Error Total…arrow_forwardThe article "Experimental Measurement of Radiative Heat Transfer in Gas-Solid Suspension Flow System" (G. Han, K. Tuzla, and J. Chen, AIChe Journal, 2002:1910- 1916) discusses the calibration of a radiometer. Several measurements were made on the electromotive force readings of the radiometer (in volts) and the radiation flux (in kilowatts per square meter). The results (read from a graph) are presented in the following table. Heat flux (y) 15 31 51 55 67 89 Signal output (x) 1.08 2.42 4.17 4.46 5.17 6.92 Compute the least-squares line for predicting heat flux from the signal output. If the radiometer reads 3.00 V, predict the heat flux. If the radiometer reads 8.00 V, should the heat flux be predicted? If so, predict it. If not, explain why. C.arrow_forward
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