Given α = 0.8, calculate the right-tailed and left-tailed critical value for Z
Calculate right-tailed value:
Since α = 0.8, the area under the curve is 1 - α → 1 - 0.8 = 0.2
Our critical z value is -0.8416
Excel or Google Sheets formula:
=NORMSINV(0.2)
Calculate left-tailed value:
Our critical z-value = 0.8416
Excel or Google Sheets formula:
=NORMSINV(0.8)
z
Probability (Area under Curve)
-2.3263
0.01
-2.0537
0.02
-1.8808
0.03
-1.7507
0.04
-1.6449
0.05
-1.5548
0.06
-1.4758
0.07
-1.4051
0.08
-1.3408
0.09
-1.2816
0.10
-1.2265
0.11
-1.175
0.12
-1.1264
0.13
-1.0803
0.14
-1.0364
0.15
-0.9945
0.16
-0.9542
0.17
-0.9154
0.18
-0.8779
0.19
-0.8416
0.20
-0.8064
0.21
-0.7722
0.22
-0.7388
0.23
-0.7063
0.24
-0.6745
0.25
-0.6433
0.26
-0.6128
0.27
-0.5828
0.28
-0.5534
0.29
-0.5244
0.30
-0.4959
0.31
-0.4677
0.32
-0.4399
0.33
-0.4125
0.34
-0.3853
0.35
-0.3585
0.36
-0.3319
0.37
-0.3055
0.38
-0.2793
0.39
-0.2533
0.40
-0.2275
0.41
-0.2019
0.42
-0.1764
0.43
-0.151
0.44
-0.1257
0.45
-0.1004
0.46
-0.0753
0.47
-0.0502
0.48
-0.0251
0.49
0
0.50
0.0251
0.51
0.0502
0.52
0.0753
0.53
0.1004
0.54
0.1257
0.55
0.151
0.56
0.1764
0.57
0.2019
0.58
0.2275
0.59
0.2533
0.60
0.2793
0.61
0.3055
0.62
0.3319
0.63
0.3585
0.64
0.3853
0.65
0.4125
0.66
0.4399
0.67
0.4677
0.68
0.4959
0.69
0.5244
0.70
0.5534
0.71
0.5828
0.72
0.6128
0.73
0.6433
0.74
0.6745
0.75
0.7063
0.76
0.7388
0.77
0.7722
0.78
0.8064
0.79
0.8416
0.80
0.8779
0.81
0.9154
0.82
0.9542
0.83
0.9945
0.84
1.0364
0.85
1.0803
0.86
1.1264
0.87
1.175
0.88
1.2265
0.89
1.2816
0.90
1.3408
0.91
1.4051
0.92
1.4758
0.93
1.5548
0.94
1.6449
0.95
1.7507
0.96
1.8808
0.97
1.96
0.975
-1.96
0.025
2.0537
0.98
2.3263
0.99
-2.5758
0.005
2.5758
0.995
How does the Critical Z-values Calculator work?
Free Critical Z-values Calculator - Given a probability from a normal distribution, this will generate the z-score critical value. Uses the NORMSINV Excel function. This calculator has 1 input.
What 1 formula is used for the Critical Z-values Calculator?
