Answer:
(a) Mean yearly temperature = 10.58
(b) 
Explanation:
Given:
The attached chart
Solving (a): The mean yearly temperature.
This is calculated as:




Solving (b): The mean July temperature.
From the chart:

Similarities
- both contain H and O
- both are compounds , (different types of atoms)
- both are formed from covalent bonds and non metals
Explanation:
A major problem with using 15 years of data to predict 100 years of data is that the 15 years could have been setting a trend, then level off.
For example, if the 15 years of data was a graph, and it was going up every year, then what if 20 years into the 100 years it stops going up? Then that means the data was invalid because there wasn't enough to base any trends off of.
You can prevent this from happening by extending the collection time of data and to reduce the amount of time that the data will be used to predict.
Hope this helps!