Excel - cooling curves?

Question

Is there a way to extrapolate a freezing point from a cooling curve in excel? Without me having to manually draw lines on the graph on paper itself?

the graph is time vs. Temp.

Answer 1

Create the graph as an XY (Scatter) with data points connected by smoothed lines, being sure to extend the x values well beyond the freezing point.  Then select the chart in the worksheet > Chart (in the tool bar) > Add Trendline.  And in the Add Trendline dialog box select the Type and Options you need.