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Finding the Fourth Proportional to 665.61, 918.56 and 385.85

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Solution

The fourth proportional to 665.61, 918.56 and 385.85 is: 532.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.61 : 918.56 = 385.85 : x
  2. Step 2: Convert to fraction form
    665.61/918.56 = 385.85/x
  3. Step 3: Cross multiply
    665.61x = 918.56 × 385.85
  4. Step 4: Simplify right side
    665.61x = 354,419.85
  5. Step 5: Solve for x
    x = 354,419.85/665.61
  6. Step 6: Final answer
    x = 532.47

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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.