Natalie performs a chemistry experiment where she requires the temperature of an ongoing reaction.

Question

Natalie performs a chemistry experiment where she requires the temperature of an ongoing reaction. The solution is 93.5°C after 3 minutes; 90°C After 5 minutes, 84.4°C after 9 minutes; 70.2°C after 18 minutes; 54.4°C after 30 minutes; 42.5°C after 37 minutes; and 24.9°C after 48 minutes.

29. Write the equation of the best- fitting line. ( round to the nearest thousandths.)

30. On average how much does the temperature decrease every five minutes?

31. If Natalie’s solution is expected to freeze at -7°C, how many minutes into the experiment should this solution freeze? ( show work that supports your prediction and round to the nearest minute.)

been stuck on this word problem for a while, and really need help. Please help me understand questions 29, 30, and 31? Thank you!

Answer 1

Hi Jessica. In order to answer these questions, you will have to use some type of program, such as MS Excel, that will help you graph a best fit line through the data.

#29: In Excel, you can input the data into a table. In the first column, enter the minutes and in the second column, enter the temperatures. From there, graph the data as a scatter-plot with temperature on the y-axis and minutes on the x-axis. Once graphed, you can add a trend line (and display the equation). This equation will be the best fit line through the data.

#30: The equation of the line from #29 will be in the form Y=mX + b. "m" will represent the slope which is the temperature change per minute. Just take the slope and multiply by 5 to calculate the the temperature change for every 5 minutes.

#31: In the equation of the line, Y represents temperature and X represents minutes. Plug in -7 for the temperature and solve for X. The X value will tell you the number of minutes it will take for the solution to freeze.

Feel free to reach out to me directly if you need additional guidance.

-Prasad