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Finding the Fourth Proportional to 666.20, 918.96 and 518.60

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Solution

The fourth proportional to 666.20, 918.96 and 518.60 is: 715.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.20 : 918.96 = 518.60 : x
  2. Step 2: Convert to fraction form
    666.20/918.96 = 518.60/x
  3. Step 3: Cross multiply
    666.20x = 918.96 × 518.60
  4. Step 4: Simplify right side
    666.20x = 476,572.66
  5. Step 5: Solve for x
    x = 476,572.66/666.20
  6. Step 6: Final answer
    x = 715.36

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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.