Russian Oil Revenues The price of crude oil during the period 2000–2010 can be approximated by
In year t, where
Use these models to estimate Russia’s daily oil revenue and also its rate of change in 2005. (Round your answers to the nearest $1 million.)
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Applied Calculus
- The populations P (in thousands) ofHorry County, South Carolina, from 1971 through 2014can be modeled byP = 76.6e0.0313twhere t represents the year, with t = 1 corresponding to1971. (Source: U.S. Census Bureau)(a) Use the model to complete the table. (b) According to the model, when will the populationof Horry County reach 360,000?(c) Do you think the model is valid for long-termpredictions of the population? Explain.arrow_forwardIn Exercises 7–12, describe the relationship between the two quantities.arrow_forwardWorld Military Expenditure The following chart shows total military and arms trade expenditure from 2011–2020 (t = 1 represents 2011). †A bar graph titled "World military expenditure" has a horizontal t-axis labeled "Year since 2010" and a vertical axis labeled "$ (billions)". The bar graph has 10 bars. Each bar is associated with a label and an approximate value as listed below. 1: 1,800 billion dollars 2: 1,775 billion dollars 3: 1,750 billion dollars 4: 1,730 billion dollars 5: 1,760 billion dollars 6: 1,760 billion dollars 7: 1,850 billion dollars 8: 1,900 billion dollars 9: 1,950 billion dollars 10: 1,980 billion dollars (a) If you want to model the expenditure figures with a function of the form f(t) = at2 + bt + c, would you expect the coefficient a to be positive or negative? Why? HINT [See "Features of a Parabola" in this section.] We would expect the coefficient to be positive because the curve is concave up. We would expect the coefficient to be negative because the…arrow_forward
- The average amount A (in pounds per person) of fish and shellfish consumed in the UnitedStates during the period 1992–2001 can be modeled by A = (3.2x + 260)/(52x + 3800) where x is the number of years since 1992.Rewrite the model so that it has only whole number coefficients. Then simplify the model.arrow_forwardCell Phones Using the CTIA Wireless Survey for1985–2009, the number of U.S. cell phone subscribers (in millions) can be modeled byy = 0.632x2 - 2.651x + 1.209where x is the number of years after 1985.a. Graphically find when the number of U.S.subscribers was 301,617,000.b. When does the model estimate that the number ofU.S. subscribers would reach 359,515,000?c. What does the answer to (b) tell about this model?arrow_forward2. Lijah opened an account at Advantis Credit Union. The balance of her account after x years is represented by the function b(x) = 500(1.05)*. What annual interest rate is Lijah earning? а. b. After how many years did it take for Lijah's balance to double? Show all of your work.arrow_forward
- Sec3.4#55arrow_forwardSolve the equation for x algebricallyarrow_forwardLet y be the percent increase in annual US national production during a year when the unemployment rate changes by u percent. (For example, u=2 if unemployment increases from 4% to 6%.) Okun's law states that y=3.5-2u. (a) What is the meaning of the number 3.5 in Okun's law? (b) What is the effect on national production of a year when unemployment rises from 4% to 8%? (c) What change in the unemployment rate corresponds to a year when production is the same as the year before?Enter the exact answer as a positive value. (d) What is the meaning of the coefficient -2 in Okun's law?arrow_forward
- what percentage of years will have an annual rainfall of less than 44 inches ? what percentage of years will have an annual rainfall of more than 39 inches ? what percentage of years will have an annual rainfall of between 38 inches and 42 inches mean+ 41.9 standard devitation 6.1arrow_forwardThe capacities at which U.S. nuclear power plants are working are shown in table for various years. Year Percent 1975 56 1980 59 1985 58 1990 70 1995 76 2000 88 2004 89 Let f(t) be the capacity (in percent) at which U.S. nuclear power plants are working at t years since 1970. A model of the situation is f(t)=0.027t^2+0.216t+53.296. Estimate at what capacity U. S. nuclear power plants were working in 2012? (Round to the nearest whole percent) __________% Predict when U. S. nuclear power plants will be working at full (100%) capacity? (Enter the year this occurs.) __________arrow_forward|The amount A(t) of atmospheric pollutants in a certain mountain valley grows naturally and is tripling every 7.5 years. If it will be dangerous to stay in the valley when the amount of pollutants reaches 100 pu, how long will this take?arrow_forward
- Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage