5 Remove the legend and gridlines from the chart.
6 Change the chart title to Average Global Temperature. Change the
x axis title to Year and the y axis title to Temperature (F). Figure 11-2
shows the edited chart.Figure 11-2
Time plot of
annual global
temperatures
The plot in Figure 11-2 shows a noticeable increase in mean annual tem-
perature over the second half of the twentieth century. While the trend is strik-
ing, there is still a great deal of variability in the average annual temperature
from year to year. We can smooth out this variability by plotting the averages
per decade.To calculate the average global temperature per decade:1 Click the Temperature sheet tab.
2 Click Descriptive Statistics from the StatPlus menu and then click
Univariate Statistics.
3 Click the Summary tab and select the Count and Average checkboxes.
4 Click the Variability tab and select the Range and Std. Deviation
checkboxes.434 Statistical Methods