MATH 225N Statistics correlation and Y intercepts, Verified Answers
MATH 225N Statistics correlation and Y intercepts. 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? year dollars dollars per year years per dollar television model Question Which of the following data sets or plots could have a regression line with a negative y-intercept? Select all that apply. • 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. 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. 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? 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.
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math 225n statistics correlation and y intercepts
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statistics correlation and y intercepts
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a plot of time versus the price of a best selling model of television has horizontal units of years since 2000
