The article “Stochastic Modeling for Pavement Warranty Cost Estimation” (J. of Constr. Engr. and Mgmnt., 2009: 352–359) proposes the following model for the distribution of Y = time to pavement failure. Let \(\displaystyle{X}_{{{1}}}\) be the time to failure due to rutting, and \(\displaystyle{X}_{{{2}}}\) be the time to failure due to transverse cracking, these two rvs are assumed independent. Then \(\displaystyle{Y}=\min{\left({X}_{{{1}}},{X}_{{{2}}}\right)}\). The probability of failure due to either one of these distress modes is assumed to be an increasing function of time t. After making certain distributional assumptions, the following form of the cdf for each mode is obtained: \(\displaystyle\Phi{\left[\frac{{{a}+{b}{t}}}{{\left({c}+{\left.{d}{t}\right.}+{e}{t}^{{{2}}}\right)}^{{\frac{{1}}{{2}}}}}\right]}\) where \(\Uparrow \Phi\) is the standard normal cdf. Values of the five parameters a, b, c, d, and e are -25.49, 1.15, 4.45, -1.78, and .171 for cracking and -21.27, .0325, .972, -.00028, and .00022 for rutting. Determine the probability of pavement failure within \(\displaystyle{t}={5}\) years and also \(\displaystyle{t}={10}\) years.
Which possible statements about the chi-squared distribution are true?
a) The statistic
b) The sum of the squares of k independent standard normal random variables has a Chi-squared distribution with k degrees of freedom.
c) The Chi-squared distribution is used in hypothesis testing and estimation.
d) The Chi-squared distribution is a particular case of the Gamma distribution.
e)All of the above.
Use the table from the Theoretical Distribution section to calculate the following answers. Round your answers to four decimal places.
A kickball's height h (in feet) t seconds after it is kicked off the ground is represented by the function (in math terms). Calculate the kickball's highest point. b) Locate and examine the symmetry axis.
The table shows the population of various cities, in thousands, and the average walking speed, in feet per second, of a person living in the city.
True or false to each of the statements in parts (a) and (b), and explain your reasoning. a. Two data sets that have identical frequency distributions have identical relative-frequency distributions. b. Two data sets that have identical relative-frequency distributions have identical frequency distributions. c. Use your answers to parts (a) and (b) to explain why relativefrequency distributions are better than frequency distributions for comparing two data sets.