Reaction time for a group of people is normally distributed, with a mean of 0.9 seconds and a standard deviation of 0.1 seconds. Find the probability that an individual selected at random has a reaction time less than 1 second. Round your answer to four decimal places.
A)0.3413
B)0.6587
C)0.1587
D)0.8413
E)0.6826

Question

Reaction time for a group of people is normally distributed, with a mean of 0.9 seconds and a standard deviation of 0.1 seconds. Find the probability that an individual selected at random has a reaction time less than 1 second. Round your answer to four decimal places. ​
A)0.3413
B)0.6587
C)0.1587
D)0.8413
E)0.6826

Quizplus · Accepted Answer

We need to find the probability that an individual has a reaction time less than 1 second. Using the given information, we can standardize the value using the formula z = (x - μ) / σ, where x is the value we want to standardize, μ is the mean, and σ is the standard deviation. Thus, we get z = (1 - 0.9) / 0.1 = 1. The standard normal table gives the probability that a standard normal variable is less than 1 as 0.8413. Therefore, the probability that an individual selected at random has a reaction time less than 1 second is 0.8413.

Reaction Time for a Group of People Is Normally Distributed