31.naturally erode and decay making it easier to break. Because of this, we should expect:It makes common sense that as the age of something like concrete goes up, it woulda) the correlation coefficient between age and load to be negative and the slope of the regression line to be positiveb) the correlation coefficient between age and load to be positive and the slope of the regression line to positivec) the correlation coefficient between age and load to be negative and the slope of the regression line to be negatived) the correlation coefficient between age and load to be positive and the slope of the regression line to be negativee) the correlation coefficient between age and load to be near zero and the slope of the regression line to be flat32.A structural engineer hires you to predict the load necessary to crack the concrete if it isfive years old. What do you tell the engineer?a) The road is so young that we wouldn't expect any erosion. So, predict the load to be highest seen in thedata set which is 11b) By using the line of best fit equation, when the age of the concrete is five, the regression line predicts theload to be 13.06.c) Since a road that is five years old is 14 the age of a 20 year old road, we should predict the load to be 14 of11, which is 2.75.d) Since the road is so young, it should not have any defects or cracks at all at such a young age, so it shouldbe able to hold a near infinite load.e) No data in this experiment was collected for roads that are close to five years old, so we have noinformation available to us in order to make this prediction. We should not make this prediction at all.33.DO NOT ACTUALLY DO A HYPOTHESIS TEST TO ANSWER THISQUESTION. Based on all of the information from the previous questions associated with this data set, whatwould the final conclusion be if we tested H₁ : ₁ = 0 vs. H₁:³₂ ±0 ?a) We would not reject the null hypothesis. The trend between age and load can be taken to have a zero slopeb) We would reject the null hypothesis because clearly the trend between age and load has a positive slopec) We would reject the null hypothesis because clearly the trend between age and load has a negative sloped) We would not reject the null hypothesis because the correlation between age and load is zero.e) We would not reject the null hypothesis because the slope of the regression line is flat.34.In the context of this application, the appropriate sampling distribution to use in aconfidence interval for the slope or hypothesis test for the slope isa) zd) a t distribution with 4 df35.b) a t distribution with 6 dfe) a t distribution with 10 dfc) a t distribution with 5 dfDO NOT ACTUALLY DO A CONFIDENCE INTERVAL TO ANSWER THISQUESTION. Based on all of the information from the previous questions associated with this data set, whatfeature would a confidence interval for the slope have in this context?a) The confidence interval would be entirely consisting of negative valuesb) The confidence interval would be entirely consisting of positive valuesc) The confidence interval would include the value 0d) The lower bound of the confidence interval would be positive and the upper bound would be negativee) The lower bound of the confidence interval would be 0 and the upper bound would be $₁. Calculations Scenario #1Read the following paragraph and examine the following data set and then answer Questions 25-35.Tax dollars are spent to help enhance the quality of the roads we drive on. A study was done looking at howthe age of concrete is related to the load necessary to crack the slab of the roadway. Ultimately, we wouldlike to predict the load necessary to create a crack from knowing the age of the concrete. The collecteddata on age (in years) and load (in 1000 lb./ft) are as follows:AgeLoad202225303240Total: 16925.11.0010.9927.10.85a) 7.386910.099.40The scatterplot for the data given above shows what type of trend?a) a nonlinear trend such that as age increases the load that the concrete can handle decreasesb) a very weak overall trend, but one that has load increase for roads that are young.c) a very strong linear trend with a negative sloped) a linear trend in which the load necessary to create a crack is increasing as the age increasese) a nonlinear pattern that illustrates an upward curved trend so that large loads are paired with older roads8.75Total: 61.0826.By using the scatterplot for the data given, the load required to create a crack in theconcrete if the age of the road is 35 years old isb) Between 9 and 10a) Between 8 and 9e) Less than 8c) Between 10 and 11c) 54.566d) Greater than 11The standard deviation for the data on the ages of the roads isb) near 1d) near 10e) 6.743328, 29 and 30. This question is worth three regular multiple choice questions.LEAVE # 28-#30 BLANK ON YOUR BUBBLE SHEET. INSTEAD ANSWER THE FOLLOWING:The standard deviation for the data on the loads is .9423 and the correlation coefficient between age and theload is -,9738.Given this information, find the formula for the line of best fit that goes through your scatterplot. Showall your work. Do this either at the BOTTOM of your bubble sheet or the very TOP of a fresh pieceof paper and label your answer "#28-#30"

When the two variables are said to be associated with each other when there is relationship between…

Tax dollars are spent to help enhance the quality of the roads we drive on. A study was done looking at how the age of concrete is related to the load necessary to crack the slab of the roadway. Ultimately, we would like to predict the load necessary to create a crack from knowing the age of the concrete. The collected data on age (in years) and load (in 1000 lb./ft) are as follows: Age 20 22 25 30 32 40 Total: 169 25. Load The scatterplot for the data given above shows what type of trend? a) a nonlinear trend such that as age increases the load that the concrete can handle decreases b) a very weak overall trend, but one that has load increase for roads that are young. c) a very strong linear trend with a negative slope d) a linear trend in which the load necessary to create a crack is increasing as the age increases e) a nonlinear pattern that illustrates an upward curved trend so that large loads are paired with older roads 11.00 10.99 10.85 10.09 27. 9.40 8.75 Total: 61.08 26. By using the scatterplot for the data given, the load required to create a crack in the concrete if the age of the road is 35 years old is b) Between 9 and 10 a) 7.3869 a) Between 8 and 9 e) Less than 8 c) Between 10 and 11 d) Greater than 11 The standard deviation for the data on the ages of the roads is b) near 1 c) 54.566 d) near 10 e) 6.7433

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P