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Finding the Fourth Proportional to 640.37, 879.87 and 509.15

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Solution

The fourth proportional to 640.37, 879.87 and 509.15 is: 699.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.37 : 879.87 = 509.15 : x
  2. Step 2: Convert to fraction form
    640.37/879.87 = 509.15/x
  3. Step 3: Cross multiply
    640.37x = 879.87 × 509.15
  4. Step 4: Simplify right side
    640.37x = 447,989.92
  5. Step 5: Solve for x
    x = 447,989.92/640.37
  6. Step 6: Final answer
    x = 699.58

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.