Ask Question
19 September, 14:39

The length of a text messaging conversation is normally distributed with a mean of 10 minutes and a standard deviation of 4 minutes. What is the probability that a conversation lasts longer than 20 minutes?

+3
Answers (1)
  1. 19 September, 16:54
    0
    The standard of deviation is 4.

    The mean is 10

    20 minutes - 10 (the mean) = 10 minutes longer than the mean.

    10 minutes longer / 4 minutes (deviation) = 2.5 standard deviations.

    2.5 on the Z-table = 0.9938

    The probability of being more than 20 minutes = 1 - 0.9938 = 0.0062 (0.62%)
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “The length of a text messaging conversation is normally distributed with a mean of 10 minutes and a standard deviation of 4 minutes. What ...” in 📘 Mathematics if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers