Excel NORMDIST function

The normal probability distribution function can be obtained in Microsoft Excel by using the NORMDIST function and supplying the desired mean and standard deviation. The cumulative value can also be determined. In MATLAB, the corresponding command is randn. 

The Microsoft Excel function NORMDIST(X, jx, o-, 1) gives the probability that x < p. 

Solution We need to find the fraction of the area of the Gaussian curve between x = 900 and x = / 000 h. The function NORMDIST in Excel gives the area of the curve from —oo up to a specified point, x. Here is the strategy We will find the area from v- to 900 h, which is the shaded area to the left of 900 h in Figure 4-4. Then we will find the area from — oo to 1 000 h, which is all the shaded area to the left of 1 000 h in Figure 4-4. The difference between the two is the area from 900 to 1 000 h ... 

From a In(Ar) versus %B graph the retention factors can be calculated for each (not measured) mixing ratio %B and thus for a given column dimension the retention times. With the retention times, the corresponding isocratic chromatogram can be visualized. The simulation of chromatograms from the report data is done with the Excel function Normdist [10]. 

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