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Finding the Fourth Proportional to 678.64, 1,018.52 and 432.56

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Solution

The fourth proportional to 678.64, 1,018.52 and 432.56 is: 649.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.64 : 1,018.52 = 432.56 : x
  2. Step 2: Convert to fraction form
    678.64/1,018.52 = 432.56/x
  3. Step 3: Cross multiply
    678.64x = 1,018.52 × 432.56
  4. Step 4: Simplify right side
    678.64x = 440,571.01
  5. Step 5: Solve for x
    x = 440,571.01/678.64
  6. Step 6: Final answer
    x = 649.20

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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.