The scores on a certain exam are normally distributed with a mean of 50 and a standard deviation of 10. a. What is the probability that a randomly selected student scored more than 65 on the exam? b. What percentage of students scored between 45 and 55?
Added by John D.
Step 1
The z-score is calculated by subtracting the mean from the value and then dividing by the standard deviation. So, the z-score for 65 is (65-50)/10 = 1.5. Looking up 1.5 on the z-table, we find that the probability of a z-score being less than 1.5 is approximately Show more…
Show all steps
Close
Your feedback will help us improve your experience
Tim Thornhill and 69 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Lucas F.
The final exam scores in a statistics class were normally distributed with a mean of 70 and a standard deviation of five. What is the probability that a student scored less than 55% on the exam?
Ahmet Y.
Jainendra O.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD