MATH 225N Stat correlation and Y-intercepts Quiz 2020 – Chamberlain College of Nursing | MATH225N Stat correlation and Y-intercepts Quiz 2020

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MATH 225N Stat correlation and Y-intercepts Quiz 2020 – Chamberlain College of Nursing Question   A plot of time versus the price of a best-selling model of television has horizontal units of ... years since 2000 and vertical units of dollars. The best fit line of the data are defined by the equation y=−75x+550, where x=year and y=price.   What are the units of the slope? Perfect. Your hard work is paying off ? year dollars dollars per year years per dollar television model Answer Explanation The slope of the best fit line has units of dollars per year because the line represents the number of dollars the price drops each year. The price decreases as opposed to increases because the slope is negative. Question Which of the following data sets or plots could have a regression line with a negative y-intercept? Select all that apply. Great work! That's correct. • the percent change in the land area in the arctic circle covered by ice as a function of the tons of CO2 produced by humans • • the change in the square mileage in the arctic circle covered by ice as a function of the tons of CO2 produced by humans • • the number of people living on a volcanic island as a function of the number of days since the last volcanic eruption • • the difference in the number of ships launched by competing ship builders as a function of the number of months since the start of last year • Question The scatter plot below shows the average cost of a designer jacket in a sample of years between 2000 and 2015. The least squares regression line modeling this data is given by yˆ=−4815+3.765x.   A scatterplot has a horizontal axis labeled Year from 2005 to 2015 in increments of 5 and a vertical axis labeled Price ($) from 2660 to 2780 in increments of 20. The following points are plotted: (2003, 2736); (2004, 2715); (2007, 2675); (2009, 2719); (2013, 270). All coordinates are approximate.    Interpret the slope of the least squares regression line. Yes that's right. Keep it up! The average cost of a designer jacket decreased by $3.765 each year between 2000 and 2015. The average cost of a designer jacket increased by $3.765 each year between 2000 and 2015. The average cost of a designer jacket decreased by $4815 each year between 2000 and 2015. The average cost of a designer jacket increased by $4815 each year between 2000 and 2015. Question The scatter plot below shows data for the average cost of a high-end computer (y, in dollars) in the year x years since 2000. The least squares regression line is given by yˆ=−1677+314x.   A coordinate plane has a horizontal x-axis labeled Year from 4 to 12 in increments of 2 and a vertical y-axis labeled Cost in dollars from 0 to 2000 in increments of 500. The following points are plotted: left-parenthesis 6 comma 250 right-parenthesis, left-parenthesis 7 comma 550 right-parenthesis, left-parenthesis 9 comma 1000 right-parenthesis, left-parenthesis 10 comma 1300 right-parenthesis, and left-parenthesis 11 comma 2000 right-parenthesis. A line rises from left to right, passing through left-parenthesis 7 comma 550 right-parenthesis and left-parenthesis 10 comma 1500 right-parenthesis. All coordinate are approximate.   Interpret the y-intercept of the least squares regression line. That's incorrect - mistakes are part of learning. Keep trying! The predicted cost of a computer in the year 0 is −$1677. The predicted cost of a computer in the year 2000 is $314. The predicted cost of a computer in the year 2000 is $1677. The y-intercept should not be interpreted. Question The scatter plot below shows the average cost of a designer jacket in a sample of years between 2000 and 2015. The least squares regression line modeling this data is given by yˆ=−4815+3.765x.   A scatterplot has a horizontal axis labeled Year from 2005 to 2015 in increments of 5 and a vertical axis labeled Price ($) from 2660 to 2780 in increments of 20. The following points are plotted: (2003, 2736); (2004, 2715); (2007, 2675); (2009, 2719); (2013, 270). All coordinates are approximate.    Interpret the y-intercept of the least squares regression line. Is it feasible? Correct! You nailed it. The y-intercept is −4815, which is not feasible because a product cannot have a negative cost. The y-intercept is 3.765, which is not feasible because an expensive product such as a designer jacket cannot have such a low cost. The y-intercept is −4815, which is feasible because it is the value from the regression equation. The y-intercept is 3.765 which is feasible because a product must have a positive cost. [Show More]

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