Answer:
1.
Looking at the data distribution, we see that Sarah has mostly scored under 79 seconds (9 out of 10 results) and Katie has mostly scored over 78 seconds (9 out of 10 results).
This confirms Sarah is faster.
2.
Sun City population average rate of change:
- (9500 - 20000)/(1995 - 1980) = -10500/15 = -700
This is indicating that between 1980 and 1995 the population reduced at a rate of 700 people a year.