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Finding the Fourth Proportional to 520.80, 718.64 and 287.92

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Solution

The fourth proportional to 520.80, 718.64 and 287.92 is: 397.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.80 : 718.64 = 287.92 : x
  2. Step 2: Convert to fraction form
    520.80/718.64 = 287.92/x
  3. Step 3: Cross multiply
    520.80x = 718.64 × 287.92
  4. Step 4: Simplify right side
    520.80x = 206,910.83
  5. Step 5: Solve for x
    x = 206,910.83/520.80
  6. Step 6: Final answer
    x = 397.29

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.