Use the following information for questions:
The average time taken to complete an exam, X, follows a normal probability distribution with mean = 60 minutes and standard deviation 30 minutes.
-What is the probability that a randomly chosen student will complete the exam in 30 minutes or less?
A) 0.1587
B) 0.5000
C) 0.8413
D) 0.9772

Question

Use the following information for questions:
 The average time taken to complete an exam, X, follows a normal probability distribution with mean = 60 minutes and standard deviation 30 minutes.
-What is the probability that a randomly chosen student will complete the exam in 30 minutes or less?
A) 0.1587
B) 0.5000
C) 0.8413
D) 0.9772

Quizplus · Accepted Answer

To find the probability that a student completes the exam in 30 minutes or less, we calculate the Z-score for X = 30 using the formula Z = (X - mean) / standard deviation = (30 - 60) / 30 = -1. The probability corresponding to Z = -1 (looking up in a standard normal distribution table or using a calculator) is approximately 0.1587. This means there's a 15.87% chance a student will finish in 30 minutes or less.

Use the Following Information for Questions