Values of modulus of elasticity (MOE, the ratio of stress, i.e., force per unit area, to strain, i.e., deformation per unit length, in GPa) and flexural strength (a measure of the ability to resist failure in bending, in MPa) were determined for a sample of concrete beams of a certain type, resulting in the following data (read from a graph in the article “Effects of Aggregates and Microfillers on the Flexural Properties of Concrete,” Magazine of Concrete Research, 1997: 81–98):
MOE | 29.8 | 33.2 | 33.7 | 35.3 | 35.5 | 36.1 | 36.2 |
Strength | 5.9 | 7.2 | 7.3 | 6.3 | 8.1 | 6.8 | 7.0 |
MOE | 36.3 | 37.5 | 37.7 | 38.7 | 38.8 | 39.6 | 41.0 |
Strength | 7.6 | 6.8 | 6.5 | 7.0 | 6.3 | 7.9 | 9.0 |
MOE | 42.8 | 42.8 | 43.5 | 45.6 | 46.0 | 46.9 | 48.0 |
Strength | 8.2 | 8.7 | 7.8 | 9.7 | 7.4 | 7.7 | 9.7 |
MOE | 49.3 | 51.7 | 62.6 | 69.8 | 79.5 | 80.0 |
Strength | 7.8 | 7.7 | 11.6 | 11.3 | 11.8 | 10.7 |
- a. Construct a stem-and-leaf display of the MOE values. and comment on any interesting features.
- b. Is the value of strength completely and uniquely determined by the value of MOE? Explain.
- c. Use the accompanying Minitab output to obtain the equation of the least squares line for predicting (strength from modulus of elasticity, and then predict strength for a beam whose modulus of elasticity is 40. Would you feel comfortable using the least squares line to predict strength when modulus of elasticity is 100? Explain.
Predictor | Coef | stdev | t-ratio | P |
Constant | 3.2925 | 0.6008 | 5.48 | 0.000 |
mod elas | 0.10748 | 0.01280 | 8.40 | 0.000 |
Analysis of Variance
SOURCE | DF | SS | MS | F | P |
Regression | 1 | 52.870 | 52.870 | 70.55 | 0.000 |
Error | 25 | 18.736 | 0.749 | ||
Total | 26 | 71.605 |
d. What are the values of SSE, SST. and the coefficient of determination? Do these values suggest that the simple linear regression model effectively describes the relationship between the two variables? Explain.
Trending nowThis is a popular solution!
Chapter 12 Solutions
Probability and Statistics for Engineering and the Sciences
- Spacers are manufactured to the mean dimension and tolerance shown in Figure 29-12. An inspector measures 10 spacers and records the following thicknesses: 0.372" 0.376" 0.379" 0.375" 0.370" 0.373" 0.377" 0.378" 0.371" 0.380" Which spacers are defective (above the maximum limit or below the minimum limit)? All dimensions are in inches.arrow_forwardA study was done to compare the flu incidence rates at the sart and at the end of winter of a given year. A sample of 100 persons were asked for incidence of flu twice: once at the start and once at the end of winter. Sample data were as follows: a. Give 99% CI for the difference in flu incidence rates at the start and at the end of winter? b. Compute a measure of association between flue incidence at the start and at the end of winter?arrow_forwardAnalysis of several plant-food preparations for potassium ion yielded the following data:arrow_forward
- If Elliot collects data from a single sample and her dependent variable is assessed on a nominal scale, which of these difference tests would Elliot need to use to analyze her data? A. a single-sample t test B. a single-sample z test C. a between-subjects ANOVA D. a chi-square goodness-of-fit testarrow_forwardHow sensitive to changes in water temperature are coral reefs? To find out, scientists examined data on sea surface temperatures and coral growth per year at locations in the Gulf of Mexico and the Caribbean Sea. The table shows the data for the Gulf of Mexico. Sea surface temperature 26.726.7 26.626.6 26.626.6 26.526.5 26.326.3 26.126.1 Growth 0.850.85 0.850.85 0.790.79 0.860.86 0.890.89 0.920.92 Click to download the data in your preferred format. CSV Excel JMP Mac-Text Minitab14-18 Minitab18+ PC-Text R SPSS TI CrunchIt! © Macmillan Learning (a) Make a scatterplot. Which is the explanatory variable? The plot shows a negative linear pattern. Explanatory Variable: How sensitive to changes in water temperature are coral reefs? To find out, scientists examined data on sea surface temperatures and coral growth per year at locations in the Gulf of Mexico and the Caribbean Sea. The table shows the data…arrow_forwardKaitlyn measures the upload speed in megabits per second of her home broadband internet connection during peak hours and off-peak hours. The results are provided in the accompanying table. Peak Off-Peak 5.83 5.14 6.05 6.80 7.14 6.98 3.54 5.77 5.45 7.27 5.90 6.62 5.81 6.19 4.82 6.08 6.37 6.59 4.65 5.58 5.30 7.41 6.48 6.26 5.96 6.37 5.79 6.31 6.84 6.55 5.06 4.95 5.61 7.03 6.45 6.77 Examine the results of Kaitlyn's test to determine the statements that compare the medians and interquartile ranges of the data sets to each other in terms of this situation. Select the two correct answers. The median upload speed during peak hours is 5.905 megabits per second, which is less than the median upload speed during off-peak hours, 7.005 megabits per second. The upload speeds during peak hours are slower on average compared to off-peak times. The median upload speed during peak hours is 6.37 megabits per second, which is greater than the median upload speed during…arrow_forward
- Mathematics For Machine TechnologyAdvanced MathISBN:9781337798310Author:Peterson, John.Publisher:Cengage Learning,Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill