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Finding the Fourth Proportional to 665.31, 918.14 and 385.55

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Solution

The fourth proportional to 665.31, 918.14 and 385.55 is: 532.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.31 : 918.14 = 385.55 : x
  2. Step 2: Convert to fraction form
    665.31/918.14 = 385.55/x
  3. Step 3: Cross multiply
    665.31x = 918.14 × 385.55
  4. Step 4: Simplify right side
    665.31x = 353,988.88
  5. Step 5: Solve for x
    x = 353,988.88/665.31
  6. Step 6: Final answer
    x = 532.07

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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.