The probability of false alarm is defined as

The probability of false alarm is defined as

• A. Probability of incorrectly identifying a tight tank as leaking
• B. Probability of correctly identifying a tight tank as leaking
• C. Probability of incorrectly identifying a leaking tank as tight
• D. Probability of failing to identify a leak

Answer: (A)

In tightness testing, a false alarm is when the test indicates a leak even though the tank isn’t leaking. So the probability of a false alarm is the chance that a tight tank is identified as leaking. This is the best description because it captures the idea of a false positive: declaring a problem when none exists. If a leaking tank is correctly identified as leaking, that’s a true detection. If a leaking tank is missed, or a tight tank is called tight, those are not false alarms.

In tightness testing, a false alarm is when the test indicates a leak even though the tank isn’t leaking. So the probability of a false alarm is the chance that a tight tank is identified as leaking. This is the best description because it captures the idea of a false positive: declaring a problem when none exists. If a leaking tank is correctly identified as leaking, that’s a true detection. If a leaking tank is missed, or a tight tank is called tight, those are not false alarms.