Question

The length of a text messaging conversation is normally distributed with a mean of 2 minutes and a standard deviation of .5 minutes. What is the probability that a conversation lasts longer than 3 minutes? (1 point)

0.043351
0.063748
0.02275
0.095424

Answer 1

The correct answer is 0.063748.

We can use the formula Z = (x - μ) / σ to find the Z score for a conversation lasting longer than 3 minutes. We know that μ = 2 minutes and σ = .5 minutes. So, Z = (3 minutes - 2 minutes) / .5 minutes = 1.0. Now, we can use the z-score table to find the probability that a conversation lasts longer than 3 minutes. The z-score table shows that the probability that a conversation lasts longer than 3 minutes is 0.063748.