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Finding the Fourth Proportional to 612.38, 918.90 and 287.78

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Solution

The fourth proportional to 612.38, 918.90 and 287.78 is: 431.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.38 : 918.90 = 287.78 : x
  2. Step 2: Convert to fraction form
    612.38/918.90 = 287.78/x
  3. Step 3: Cross multiply
    612.38x = 918.90 × 287.78
  4. Step 4: Simplify right side
    612.38x = 264,436.45
  5. Step 5: Solve for x
    x = 264,436.45/612.38
  6. Step 6: Final answer
    x = 431.82

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.