The accompanying table shows the operating revenue, in millions of dollars, of wired and wireless telecommunications carriers in the United States in the given year.†
| Year | Wired | Wireless |
|---|---|---|
| 2005 | 205.7 | 140.0 |
| 2006 | 195.6 | 157.5 |
| 2007 | 197.0 | 173.8 |
| 2008 | 194.8 | 184.8 |
(a) Calculate the regression line for each type of carrier. (Let t be the time in years since 2005, R be the operating revenue of wired carriers and L be the revenue of wireless carriers. Round your regression parameters to two decimal places.)
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R =
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L =
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(b) Determine the revenue level at which the two lines cross. Round your answer for the revenue level to one decimal place.
______ million dollars

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