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Finding the Fourth Proportional to 499.14, 689.15 and 312.70

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Solution

The fourth proportional to 499.14, 689.15 and 312.70 is: 431.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.14 : 689.15 = 312.70 : x
  2. Step 2: Convert to fraction form
    499.14/689.15 = 312.70/x
  3. Step 3: Cross multiply
    499.14x = 689.15 × 312.70
  4. Step 4: Simplify right side
    499.14x = 215,497.21
  5. Step 5: Solve for x
    x = 215,497.21/499.14
  6. Step 6: Final answer
    x = 431.74

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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.