Enter the data into the corrregression applet produce

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Enter the data into the Corr/Regression applet. Produce a scatterplot and comment on the association between the variables as revealed in the scatterplot. (Remember to comment on form, direction, strength, and unusual observations.) There is a fairly strong negative association between age and price of the cars. Not much unusual except perhaps the oldest and cheapest car. See scatterplot for Solution f. Report the value of the correlation coefficient. Does the value of the correlation coefficient support your answer in part (f)? Explain how you are deciding. The correlation of -0.820 backs up the answer to part (f) because it is close to -1. Describe how one might use everyday items (for example, coins, dice, cards, etc.) to conduct a tactile simulation-based test of the hypotheses. Be sure to clearly describe how the p-value will be computed from the simulation. Put the 90 ages on 90 index cards and the 90 prices on 90 other index cards. Shuffle the price index cards and randomly match them up with the 90 age cards. From this data set, compute the correlation coefficient. That simulated correlation coefficient will be one dot in the null distribution. Repeat this many, many times to create a null distribution. Find the proportion of simulated correlation coefficients that are -0.820 or below along with the simulated correlation coefficients that are 0.820 or above. This proportion will be the estimated p-value. Chapter 10.2 Exercise Question 08 Refer to the previous exercise about the association between the age and price of used Honda Civics. Consider conducting a test of significance to investigate whether the sample data provide
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strong evidence of an association between a car's price and age in the population of used Honda Civics. The data are in the file UsedHondaCivics . Enter the data into the Corr/Regression applet and conduct a simulation-based test of significance using the correlation coefficient as the statistic. Report the approximate p-value. The p-value is about 0. Interpret the p-value reported in part (a). If there is no association between age and price of used Honda Civics, the probability we would get a sample correlation coefficient at least as extreme as -0.820 is about 0. Summarize your conclusion (significance, causation, generalizability) from this simulation analysis. Also describe the reasoning process by which your conclusion follows from your simulation results. We have extremely strong evidence (small p-value) that there is an association between a car's price and its age in the population of all used Honda Civics advertised online. Because our sample correlation coefficient is negative, we can add that the association is negative in the population. Because this was an observational study, we are not drawing any causal conclusions.
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  • Summer '18
  • Null hypothesis, Statistical hypothesis testing, Correlation and dependence, Pearson product-moment correlation coefficient

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