The following table shows fuel consumption in billions of gallons of all vehicles in the U.S. for years since 1990. Year Fuel Use 0 130.8 3 137.3 6 147.4 9 161.4 12 168.7 15 174.8 18 170.8 Let F(t)F(t) be the fuel consumption in billions of gallons in t years since 1990. A quadratic model for the data is F(t)=−0.114t2+4.62t+127.598F(t)=-0.114t2+4.62t+127.598. 369121518125130135140145150155160165170175 Use the above scatter plot to decide whether the quadratic model fits the data well. The function is a good model for the data. The function is not a good model for the data Correct Estimate the fuel consumption in the U. S. in 2013.  billions of gallons. Use the model to predict the year in which U.S. fuel consumption will peak.

The below data represent the advertising expenditure and sales of Liu Liu Ltd from year 2010 to 2019. Table: Advertising Expenditure vs. Sales from 2010 to 2019   Year Advert. Expenditure   Sales Growth rate of Ad. Expenditure Growth rate of Sales   (x, £000) (y, £000)     2010 19 84     2011 22 108 18% 29% 2012 32 82 46% -24% 2013 42 86 32% 6% 2014 47 84 11% -3% 2015 46 94 -2% 11% 2016 58 103 27% 10% 2017 63 115 8% 12% 2018 70 106 11% -8% 2019 80 142 15% 34% Total 479 1004       a. What is the statistical relationship shown in the table and list out 3 characteristics of this relationship?

(Medicare). The annual expenditures for Medicare (in billions of dollars) by the US Government for selected years since 1980 are shown in Table 4. Let x represent the years since 1980. (Use 4 decimal places in all answers.) Table 4: Medicare Expenditures Year Billion $ 1980 37 1985 72 1990 111 1995 181 2000 197 2005 330 A. Find the exponential regression model for the data.M(x) =        B. What is the r2 value for this model?r2 =        C. Extimate (to the nearest billion) the expenditures in 2008?The Medicare expenditures in 2008 were about $         billion.

The idea of a large, stable middle class (defined as those with annual household incomes in 2010 between $42,000 and $126,000 for a family of three), is central to America's sense of itself. But the U.S. middle class shrank steadily from 61% of all adults in 1971  (t = 0)  to 51% in 2011  (t = 4),  where t is measured in decades. Research has shown that this decline was approximately linear.† (a) Find a linear function f(t) giving the percentage of middle-income adults in decade t, where t = 0 corresponds to 1971. (b) If this trend continues, what will the percentage of middle-income adults be in 2041?