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Finding the Fourth Proportional to 487.28, 672.48 and 312.56

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Solution

The fourth proportional to 487.28, 672.48 and 312.56 is: 431.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.28 : 672.48 = 312.56 : x
  2. Step 2: Convert to fraction form
    487.28/672.48 = 312.56/x
  3. Step 3: Cross multiply
    487.28x = 672.48 × 312.56
  4. Step 4: Simplify right side
    487.28x = 210,190.35
  5. Step 5: Solve for x
    x = 210,190.35/487.28
  6. Step 6: Final answer
    x = 431.35

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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.