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Finding the Fourth Proportional to 665.29, 918.12 and 385.57

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Solution

The fourth proportional to 665.29, 918.12 and 385.57 is: 532.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.29 : 918.12 = 385.57 : x
  2. Step 2: Convert to fraction form
    665.29/918.12 = 385.57/x
  3. Step 3: Cross multiply
    665.29x = 918.12 × 385.57
  4. Step 4: Simplify right side
    665.29x = 353,999.53
  5. Step 5: Solve for x
    x = 353,999.53/665.29
  6. Step 6: Final answer
    x = 532.10

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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.