Quality Learning Support For Better Outcomes
First time here? Checkout the FAQs!
MathsGee is Zero-Rated (You do not need data to access) on: Telkom |Dimension Data | Rain | MWEB

0 like 0 dislike
Potassium blood levels in healthy humans are normally distributed with a mean of 17.0 mg/100 ml, and standard deviation of 1.0 mg/100 ml. Elevated
levels of potassium indicate an electrolyte balance problem, such as may be caused by Addison’s disease. However, a test for potassium level should not cause too many “false positives”. What level of potassium should we use so that only 2.5 % of healthy individuals are classified as “abnormally high”?
Use normal distribution
in Data Science & Statistics by Diamond (80,728 points) | 805 views

1 Answer

2 like 0 dislike
Best answer

The phrase "normally distributed" should give a clue as to the use of Z-score table and the z-score equation which is:

You're given the standard deviation, mean and means to find the z-score.

1. You know that your data needs to exclude 2.5% of the population which means you're looking for 97.5% (0.975) look this up on your table and you get 1.96.

So now that you rearrange the equation so that x is the subject of the formula.

the answer that you get should be 18.96 mg/ 100 mL.

by Wooden (624 points)
selected by

Related questions

Join the MathsGee Answer Hub community and get study support for success - MathsGee Answer Hub provides answers to subject-specific educational questions for improved outcomes.

On MathsGee Answers, you can:

  1. Ask questions
  2. Answer questions
  3. Comment on Answers
  4. Vote on Questions and Answers
  5. Donate to your favourite users
  6. Create/Take Live Video Lessons

Posting on MathsGee

  1. Remember the human
  2. Behave like you would in real life
  3. Look for the original source of content
  4. Search for duplicates before posting
  5. Read the community's rules
MathsGee Tools

Math Worksheet Generator

Math Algebra Solver

Trigonometry Simulations

Vectors Simulations

Matrix Arithmetic Simulations

Matrix Transformations Simulations

Quadratic Equations Simulations

Probability & Statistics Simulations

PHET Simulations

Visual Statistics

MathsGee ZOOM | eBook