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Finding the Fourth Proportional to 666.78, 920.16 and 404.74

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Solution

The fourth proportional to 666.78, 920.16 and 404.74 is: 558.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.78 : 920.16 = 404.74 : x
  2. Step 2: Convert to fraction form
    666.78/920.16 = 404.74/x
  3. Step 3: Cross multiply
    666.78x = 920.16 × 404.74
  4. Step 4: Simplify right side
    666.78x = 372,425.56
  5. Step 5: Solve for x
    x = 372,425.56/666.78
  6. Step 6: Final answer
    x = 558.54

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1.5x scale

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.