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Finding the Fourth Proportional to 612.72, 918.72 and 287.64

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Solution

The fourth proportional to 612.72, 918.72 and 287.64 is: 431.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.72 : 918.72 = 287.64 : x
  2. Step 2: Convert to fraction form
    612.72/918.72 = 287.64/x
  3. Step 3: Cross multiply
    612.72x = 918.72 × 287.64
  4. Step 4: Simplify right side
    612.72x = 264,260.62
  5. Step 5: Solve for x
    x = 264,260.62/612.72
  6. Step 6: Final answer
    x = 431.29

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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.