Exponential Modeling

[thunc14]

I've assumed that temperature would be the dependent variable, and time would be the independent variable. I used minutes since 4:00 as the x values, i.e. 4:03 would be x=3, and 4:08 would be x=8. I've tried to use the two points to establish an equation, but get stuck. I've gotten down to (5/6)=b^5, but I'm not sure what to do after. It seems like this problem would be easier solved if you get the equation, graph it, and check the times listed to see which one falls below 130 degrees? How do I go about getting the equation?

 

[Steven G]

Can we see your work? This way we have an idea how you want to solve this problem as there are always multiple ways of solving a problems. Also maybe you have a slight error and we can point this out. Thanks.

 

[thunc14]

I attached the work I have so far

 

[Steven G]

Looks good to me. Now finish up by finding a and then write the final equation.

 

[thunc14]

Can we see your work? This way we have an idea how you want to solve this problem as there are always multiple ways of solving a problems. Also maybe you have a slight error and we can point this out. Thanks.

Graphing would be the easiest and fastest option for me given the equation, which leads me to answer D, 4:13