133: Chapter 7b Practice Test

Chapter 7b PRACTICE TEST
Please do the problems, then submit. You may go back in to check (and change) your answers.
If you didn't finish your homework (DelatMath) yet, please finish it tonight.

1

Write an exponential function in the form y=ab^x that goes through points (0,7) and (3,875).

1

A sample of a radioactive isotope had an initial mass of 490 mg in the year 1995 and decays exponentially over time. A measurement in the year 1998 found that the sample's mass had decayed to 240 mg.

What is the equation for this situation? Use y=a(b)^x and round b to the thousandth.

1

Using your answer from [2]:

What would be the expected mass of the sample in the year 2005, to the nearest whole number?

1

The accompanying table shows the value of a car over time that was purchased for 18500 dollars, where x is years and y is the value of the car in dollars. Write an exponential regression equation for this set of data, rounding all coefficients to the nearest ten-thousandth.

1

Using the equation from [4], determine how long it will be, to the nearest tenth of a year, until the car's value is 6000 dollars.

You can either write your work, or take a picture of the calculator screen.

1

Create a parent table for y=(\frac{1}{2})^x
Then, graph y=-6(\frac{1}{2})^x+5
Be sure to include the asymptote.

1

Create a parent table for y=3\log_4(x+5)+2
Then, graph it. Be sure to include the asymptote.

1

The accompanying table shows wind speed and the corresponding wind chill factor when the air temperature is 13°F. Write a logarithmic regression equation for this set of data, rounding all coefficients to the nearest thousandth.

1

Using the equation from [30], find the wind chill factor, to the nearest degree, when the wind speed is 22 miles per hour.

After you have submitted, and checked your answers, work on DeltaMath.

Chapter 7b PRACTICE TEST

Write an exponential function in the form y=ab^x that goes through points (0,7) and (3,875).

A sample of a radioactive isotope had an initial mass of 490 mg in the year 1995 and decays exponentially over time. A measurement in the year 1998 found that the sample's mass had decayed to 240 mg. What is the equation for this situation? Use y=a(b)^x and round b to the thousandth.

Using your answer from [2]:What would be the expected mass of the sample in the year 2005, to the nearest whole number?

The accompanying table shows the value of a car over time that was purchased for 18500 dollars, where x is years and y is the value of the car in dollars. Write an exponential regression equation for this set of data, rounding all coefficients to the nearest ten-thousandth.

Using the equation from [4], determine how long it will be, to the nearest tenth of a year, until the car's value is 6000 dollars.You can either write your work, or take a picture of the calculator screen.

Create a parent table for y=(\frac{1}{2})^xThen, graph y=-6(\frac{1}{2})^x+5Be sure to include the asymptote.

Create a parent table for y=3\log_4(x+5)+2Then, graph it. Be sure to include the asymptote.

The accompanying table shows wind speed and the corresponding wind chill factor when the air temperature is 13°F. Write a logarithmic regression equation for this set of data, rounding all coefficients to the nearest thousandth.

Using the equation from [30], find the wind chill factor, to the nearest degree, when the wind speed is 22 miles per hour.

A sample of a radioactive isotope had an initial mass of 490 mg in the year 1995 and decays exponentially over time. A measurement in the year 1998 found that the sample's mass had decayed to 240 mg.

What is the equation for this situation? Use y=a(b)^x and round b to the thousandth.

Using your answer from [2]:

What would be the expected mass of the sample in the year 2005, to the nearest whole number?

Using the equation from [4], determine how long it will be, to the nearest tenth of a year, until the car's value is 6000 dollars.

You can either write your work, or take a picture of the calculator screen.

Create a parent table for y=(\frac{1}{2})^x
Then, graph y=-6(\frac{1}{2})^x+5
Be sure to include the asymptote.

Create a parent table for y=3\log_4(x+5)+2
Then, graph it. Be sure to include the asymptote.