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Finding the Fourth Proportional to 26.60, 39.80 and 21.13

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Solution

The fourth proportional to 26.60, 39.80 and 21.13 is: 31.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    26.60 : 39.80 = 21.13 : x
  2. Step 2: Convert to fraction form
    26.60/39.80 = 21.13/x
  3. Step 3: Cross multiply
    26.60x = 39.80 × 21.13
  4. Step 4: Simplify right side
    26.60x = 840.97
  5. Step 5: Solve for x
    x = 840.97/26.60
  6. Step 6: Final answer
    x = 31.62

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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.