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Finding the Fourth Proportional to 720.90, 999.14 and 648

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Solution

The fourth proportional to 720.90, 999.14 and 648 is: 898.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.90 : 999.14 = 648 : x
  2. Step 2: Convert to fraction form
    720.90/999.14 = 648/x
  3. Step 3: Cross multiply
    720.90x = 999.14 × 648
  4. Step 4: Simplify right side
    720.90x = 647,439.48
  5. Step 5: Solve for x
    x = 647,439.48/720.90
  6. Step 6: Final answer
    x = 898.10

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.