Answer:
C) The third table. K= 5

Step-by-step explanation:
1) Below there are the missing data:
A proportional relationship through a constant k. It is obtained when we divide:

2)In this case, when we divide the temperature (T) by the time (h).

3)So, examining the table below we are searching for a ratio k common to all measures (temperatures over hour).

X must be 4.
I uploaded the photo as an answer
Answer:
1) 3.75
2)0.833333
3)3.66666
Step-by-step explanation:
See photo for Step-bystep explanation