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Finding the Fourth Proportional to 665.47, 918.39 and 385.77

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Solution

The fourth proportional to 665.47, 918.39 and 385.77 is: 532.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.47 : 918.39 = 385.77 : x
  2. Step 2: Convert to fraction form
    665.47/918.39 = 385.77/x
  3. Step 3: Cross multiply
    665.47x = 918.39 × 385.77
  4. Step 4: Simplify right side
    665.47x = 354,287.31
  5. Step 5: Solve for x
    x = 354,287.31/665.47
  6. Step 6: Final answer
    x = 532.39

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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.