Perfection Machining
Probability Calculations Using the Normal Distribution Template
Enter data only in the shaded cells
This spreadsheet is designed to calculate the probability of values equal to, or less than, a desired x value,
given the mean and standard deviation of a normally distributed variable. It uses the cumulative normal distribution
Enter the mean of the distribution in shaded cell D8 and the standard deviation in shaded cell D9. below.
Enter the desired X-value in shaded cell D10, below. The calculated z-value and probability will be seen in D11 and D12.
a. b. c.
Mean of distribution 7.6 7.6 7.6
Std deviation of distribution 0.3 0.3 0.3
(X-axis)
Probability Using
Desired x-values
Equivalent – Z Values
NORMS.DIST
5.800 -6.00 0.00000
5.850 -5.83 0.00000
5.900 -5.67 0.00000
5.950 -5.50 0.00000
6.000 -5.33 0.00000
6.050 -5.17 0.00000
6.100 -5.00 0.00000
6.150 -4.83 0.00000
6.200 -4.67 0.00000
6.250 -4.50 0.00000
6.800 -2.67 0.00383
6.850 -2.50 0.00621
6.900 -2.33 0.00982
6.950 -2.17 0.01513
7.000 -2.00 0.02275
7.050 -1.83 0.03338
7.100 -1.67 0.04779
7.150 -1.50 0.06681
7.200 -1.33 0.09121
7.250 -1.17 0.12167
7.750 0.50 0.69146
7.800 0.67 0.74751
7.850 0.83 0.79767
7.900 1.00 0.84134
7.950 1.17 0.87833
8.000 1.33 0.90879
8.050 1.50 0.93319
8.100 1.67 0.95221
8.150 1.83 0.96662
8.200 2.00 0.97725
8.250 2.17 0.98487
8.300 2.33 0.99018
8.350 2.50 0.99379
8.400 2.67 0.99617
8.450 2.83 0.99770
0.50
0.60
0.70
0.80
0.90
1.00
Cumulative Probability Function
Desired x-value 8.1 7.95 7.25
8.500 3.00 0.99865
8.550 3.17 0.99923
8.600 3.33 0.99957
9.100 5.00 1.00000
9.150 5.17 1.00000
9.200 5.33 1.00000
9.250 5.50 1.00000
9.300 5.67 1.00000
9.350 5.83 1.00000
9.400 6.00 1.00000