What is the minimum z-score required for a TEM clearance z-test?

• A. 1.0
• B. 1.65
• C. 1.96
• D. 2.0

Answer: (B)

In a TEM clearance z-test you’re usually testing in one direction—whether the measurement shows clearance below the limit—so you use a one-sided criterion. For a common 0.05 significance level, the standard normal critical value is 1.645, which is typically rounded to 1.65. This is the minimum z-score you need to declare clearance with about 95% confidence. Values below that don’t meet the one-sided 0.05 threshold.

Why the other values don’t fit: 1.0 is far from the needed cutoff and wouldn’t indicate clearance with 95% confidence. 1.96 comes from a two-sided 0.05 test and would be a stricter criterion in this context. 2.0 isn’t the standard critical value for the usual one-sided 0.05 test, so it’s not the minimum you’d typically use.