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Finding the Fourth Proportional to 666.81, 920.70 and 418.57

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Solution

The fourth proportional to 666.81, 920.70 and 418.57 is: 577.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.81 : 920.70 = 418.57 : x
  2. Step 2: Convert to fraction form
    666.81/920.70 = 418.57/x
  3. Step 3: Cross multiply
    666.81x = 920.70 × 418.57
  4. Step 4: Simplify right side
    666.81x = 385,375.10
  5. Step 5: Solve for x
    x = 385,375.10/666.81
  6. Step 6: Final answer
    x = 577.94

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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.