The table shows the times minutes taken by students: : frequency ; : frequency ; : frequency . What is an estimate of the mean time, in minutes?

Answer and explanation

Correct answer: D. 18.25

  1. Step 1: Determine the midpoints () of each class interval: for , ; for , ; for , .
  2. Step 2: Compute the sum of the products of each frequency and its corresponding class midpoint: .
  3. Step 3: Divide by the total number of students () to find the estimated mean: .
Answer
18.25.

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