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Finding the Fourth Proportional to 26.55, 39.85 and 20.86

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Solution

The fourth proportional to 26.55, 39.85 and 20.86 is: 31.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    26.55 : 39.85 = 20.86 : x
  2. Step 2: Convert to fraction form
    26.55/39.85 = 20.86/x
  3. Step 3: Cross multiply
    26.55x = 39.85 × 20.86
  4. Step 4: Simplify right side
    26.55x = 831.12
  5. Step 5: Solve for x
    x = 831.12/26.55
  6. Step 6: Final answer
    x = 31.30

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.