Quadratic Regression Models Answers

The Air Quality Index, or AQI, measures how polluted the air is in your city and assigns a number based on the quality of the air. Over 100 is “Unhealthy”. The number of days the AQI exceeds 100 in a given year is modeled by the following quadratic regression equation: Let n represent the number of days the AQI exceeds 100 in a given year. Approximately how many days did the AQI exceed 100 in the year 1988? Round to the nearest whole day. (Let t represent the number of years since 1990. Therefore, t = 0 corresponds to the year 1990.)

Make a scatter plot of the data below. Speed (mph) Stopping distance (ft) 10 12.5 20 36.0 30 69.5 40 114.0 50 169.5 60 249.0 70 325.5 Use the quadratic regression feature of a graphing calculator to find a quadratic model. Round to the nearest hundredths place. a. b. c. d. Please select the best answer from the choices provided

During one game, the Dallas Cowboys punter was called upon to punt the ball eight times. On one of these punts, the punter struck the ball at his own 30-yard line. The height, h of the ball above the field as a function of time , t, in seconds can be partially modeled by the following table: t 0 0.6 1.2 1.8 2.4 3.0 h(t) 2.50 28.56 43.10 46.12 37.12 17.60 Use your graphing calculator, to obtain a quadratic regression function for these data. Round the values of a,b, and c to four decimal places. a. c. b. d. Please select the best answer from the choices provided

Make a scatter plot of the data below. Speed (mph) Stopping distance (ft) 10 12.5 20 36.0 30 69.5 40 114.0 50 169.5 60 249.0 70 325.5 Using the quadratic regression equation predict what your stopping distance would be if you were going 80 miles per hour.

What is the value of a in the given quadratic regression equation? a. 1 c. b. d. Please select the best answer from the choices provided

The data set represents a progression of hourly temperature measurements. Use a graphing calculator to determine the quadratic regression equation for this data set. Round all coefficients to the nearest thousandth. x 0 1 2 3 4 5 y 20 16 10 0 -7 -20 Which equation best represents the quadratic regression model for this data? a. c. b. d.

Solve the problem. A ball is kicked upward with an initial velocity of 32 feet per second. The ball's height, h (in feet), from the ground is modeled by , where t is measured in seconds. How much time does the ball take to reach its highest point? What is its height at this point?

Solve the problem. A ball is kicked upward with an initial velocity of 64 feet per second. The ball's height, h (in feet), from the ground is modeled by , where t is measured in seconds. What is the practical domain in this situation? a. c. All real numbers b. d. Please select the best answer from the choices provided

Solve the problem. A jump rope held stationary by two children, one at each end, hangs in a shape that can be modeled by the equation, where h is the height (in inches) above the ground and x is the distance (in inches) along the ground measured from the horizontal position of one end. How close to the ground is the lowest part of the rope?

What is the value of b in the given quadratic regression equation?