Which Container Cool The Fastest

Question: Which container will retain internal heat the longest? More specifically, which container will cool the fastest and which will keep the highest temperature for the longest amount of time?
Hypothesis: My hypothesis is that the metal insulated mug with the lid will retain the highest temperature for the longest amount of time. Likewise, the mug that will lose heat the fastest will be the plastic mug with no lid.
Independent Variable: The variable that was purposely changed was the amount of time the mugs sat on the counter each trial.
Dependent Variable: I hypothesize that the temperature of the liquids will change after every trial administered.
Controlled Variables: The first thing that will not change at the beginning of the experiment is the
Likewise, the mug that will lose heat the fastest will be the plastic mug with no lid.
Independent Variable: The variable that was purposely changed was the amount of time the mugs sat on the counter each trial.
Dependent Variable: I hypothesize that the temperature of the liquids will change after every trial administered.
Controlled Variables: The first thing that will not change at the beginning of the experiment is the starting temperature of the liquids. Throughout the experiment the location of the liquids will stay the same. Also, the temperature of the room will stay the same. The mug that the liquids started in will not change so the results will have a more accurate reading.
Materials:
1. A plastic mug with no lid.
2. A glass mug with no lid.
3. A plastic insulated mug with a lid.
4. A metal insulated mug with a lid.
5. Hot chocolate to put in the mugs.
6. Hot water at 212F.
7. A thermometer.
8. A kettle.
9. A notebook.
10. A laptop.
11. And a