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Finding the Fourth Proportional to 720.13, 1,079.55 and 426.91

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Solution

The fourth proportional to 720.13, 1,079.55 and 426.91 is: 639.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.13 : 1,079.55 = 426.91 : x
  2. Step 2: Convert to fraction form
    720.13/1,079.55 = 426.91/x
  3. Step 3: Cross multiply
    720.13x = 1,079.55 × 426.91
  4. Step 4: Simplify right side
    720.13x = 460,867.99
  5. Step 5: Solve for x
    x = 460,867.99/720.13
  6. Step 6: Final answer
    x = 639.98

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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.