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Finding the Fourth Proportional to 903.60, 1,355.13 and 721.35

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Solution

The fourth proportional to 903.60, 1,355.13 and 721.35 is: 1,081.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    903.60 : 1,355.13 = 721.35 : x
  2. Step 2: Convert to fraction form
    903.60/1,355.13 = 721.35/x
  3. Step 3: Cross multiply
    903.60x = 1,355.13 × 721.35
  4. Step 4: Simplify right side
    903.60x = 977,523.03
  5. Step 5: Solve for x
    x = 977,523.03/903.60
  6. Step 6: Final answer
    x = 1,081.81

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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.