Answer: standard deviation
Step-by-step explanation:
Answer:
The correct answer will be:

Step-by-step explanation:
It is given that :
Initial temperature, 
Final temperature,

Time taken :

Change in temperature per hour:

Putting the values of temperatures and time:

The error done by Wen was during calculating the values of fraction.
So, the correct answer is :
instead of
6x-18
you pretty much h just multiply both the first part of the parentheses by the number outside, then the second :)
Do you mean the ratio 1:2