Inaccurate Area under normal curve
I am using geogebra to provide interactive graph of the standard normal distribution for a WeBWorK question.
The area under the curve is not being calculated with as much accuracy as I need.
P(Z<-1.91) is 0.0281 but setting the sliding point to -1.91 on the graph shows an area of 0.0274.
You can find the graph in question at https://www.geogebra.org/m/a9z9GKKB.
I have used Normal(meanPop, stdDevPop, x) to graph the function with meanPop=0 and stdDevPop=1.