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Finding the Fourth Proportional to 665.49, 918.18 and 385.72

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Solution

The fourth proportional to 665.49, 918.18 and 385.72 is: 532.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.49 : 918.18 = 385.72 : x
  2. Step 2: Convert to fraction form
    665.49/918.18 = 385.72/x
  3. Step 3: Cross multiply
    665.49x = 918.18 × 385.72
  4. Step 4: Simplify right side
    665.49x = 354,160.39
  5. Step 5: Solve for x
    x = 354,160.39/665.49
  6. Step 6: Final answer
    x = 532.18

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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.