Needs["ErrorBarPlots`"]

?ErrorListPlot

erlp = {{1,2 , 0.5},{2, 4, 1.5},{3,9, 2.2}}

ErrorListPlot[erlp, PlotRange -> {{-0.5, 3.2},{0, 12}}]

SetDirectory["/Users/peter/courses/115/mathematica"]

erlp = Import["data2"]

ErrorListPlot[erlp, PlotRange -> {{-0.5, 3.2},{0, 12}}]