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Finding the Fourth Proportional to 665.57, 918.43 and 385.81

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Solution

The fourth proportional to 665.57, 918.43 and 385.81 is: 532.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.57 : 918.43 = 385.81 : x
  2. Step 2: Convert to fraction form
    665.57/918.43 = 385.81/x
  3. Step 3: Cross multiply
    665.57x = 918.43 × 385.81
  4. Step 4: Simplify right side
    665.57x = 354,336.22
  5. Step 5: Solve for x
    x = 354,336.22/665.57
  6. Step 6: Final answer
    x = 532.38

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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.