High School

We appreciate your visit to A sniffer device for detecting gas leaks has a sensitivity of 0 99 and a specificity of 0 98 The probability of a gas leak. This page offers clear insights and highlights the essential aspects of the topic. Our goal is to provide a helpful and engaging learning experience. Explore the content and find the answers you need!

A sniffer device for detecting gas leaks has a sensitivity of 0.99 and a specificity of 0.98. The probability of a gas leak actually being present when one is suspected is 0.001. What is the probability of an actual gas leak if the sniffer detects a leak?

Answer :

Final answer:

Therefore, the probability that there is actually a gas leak when the sniffer detects one is approximately 4.72%.

Explanation:

To determine the probability of an actual gas leak if the sniffer detects a leak, we can apply Bayes' theorem, which relates the conditional and marginal probabilities of stochastic events. Given that the sensitivity (true positive rate) of the sniffer is 0.99 and the specificity (true negative rate) is 0.98, and the prior probability of there being a gas leak is 0.001, we need to calculate the posterior probability.

The formula for the posterior probability (P(A|B)) in the context of our problem is:

P(A|B) = (P(B|A) * P(A)) / [(P(B|A) * P(A)) + (P(B|not A) * P(not A))]

Where:

  • P(A) is the prior probability of a gas leak (0.001)
  • P(B|A) is the sensitivity or the probability of a positive test given a gas leak (0.99)
  • P(not A) is the probability of there being no gas leak, which is 1 - P(A) (0.999)
  • P(B|not A) is the probability of a false positive, which is 1 - specificity (0.02)

Plugging in the values:

P(A|B) = (0.99 * 0.001) / [(0.99 * 0.001) + (0.02 * 0.999)]

P(A|B) ≈ 0.0472

Therefore, the probability that there is actually a gas leak when the sniffer detects one is approximately 4.72%.

Thanks for taking the time to read A sniffer device for detecting gas leaks has a sensitivity of 0 99 and a specificity of 0 98 The probability of a gas leak. We hope the insights shared have been valuable and enhanced your understanding of the topic. Don�t hesitate to browse our website for more informative and engaging content!

Rewritten by : Barada