Probability as Expectation Math Example 3

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Example 3

easy
A school expects 15% of students to be absent on any given day. If there are 300 students, how many absences are expected?

Solution

  1. 1
    Expected count =n×P=300×0.15=45= n \times P = 300 \times 0.15 = 45 students
  2. 2
    The school should plan for approximately 45 absences per day on average

Answer

Expected absences =300×0.15=45= 300 \times 0.15 = 45 students per day.
The expected count formula translates a probability into a practical count. School administrators, hospitals, and businesses routinely use expected values for staffing, inventory, and resource planning.

About Probability as Expectation

Probability can be interpreted as the long-run relative frequency of an event over infinitely many identical trials of a random experiment.

Learn more about Probability as Expectation →

More Probability as Expectation Examples

Example 1 easy

A basketball player makes free throws with probability 0.75. In 200 free throws, how many do we expe

Example 2 medium

A game has three outcomes: win [formula]0 (prob 0.5), lose $5 (prob 0.3). Calculate the expected val

Example 4 hard

An insurance company charges [formula]10,000 if the insured event occurs (probability 0.01) and $0 o

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