You visit a local Starbucks to buy a Mocha Frappuccino. The
barista explains that this blended coffee beverage comes in three
sizes and asks if you want a 12-ounce Tall, a 16-ounce Grande, or a
24-ounce Venti. The prices are $3.95, $4.45, and $4.95,
respectively. There is a clear positive association between the
size of the Mocha Frappuccino and its price.
Plot the data.
Why should you plot size in ounces on the x
axis?
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Because price is the explanatory variable. |
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Because size is the explanatory variable. |
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Because size is the response variable. |
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Because there is a positive correlation between the
variables. |
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What is the least-squares regression line for predicting the price
using size? Add the line to your plot. Draw a vertical line from
the least squares line to each data point. This gives a graphical
picture of the residuals.
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yˆ=2.26+0.084xy^=2.26+0.084x |
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yˆ=0.0804+2.26xy^=0.0804+2.26x |
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yˆ=3.05714+0.08036xy^=3.05714+0.08036x |
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yˆ=0.08036+2.6071xy^=0.08036+2.6071x |
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What is the meaning of the middle residual being positive and the
other two negative?
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The 12-ounce and 24-ounce drinks are miss valued and should be
sold at a higher price. |
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The 16-ounce drink is expensive, and the other two sizes are
relatively cheap. |
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The 16-ounce drink costs less than the predicted value, and the
other two sizes cost more than predicted. |
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The 16-ounce drink costs more than the predicted value, and the
other two sizes cost less than predicted. |
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