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Finding the Fourth Proportional to 312.76, 434.59 and 309.38

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Solution

The fourth proportional to 312.76, 434.59 and 309.38 is: 429.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.76 : 434.59 = 309.38 : x
  2. Step 2: Convert to fraction form
    312.76/434.59 = 309.38/x
  3. Step 3: Cross multiply
    312.76x = 434.59 × 309.38
  4. Step 4: Simplify right side
    312.76x = 134,451.91
  5. Step 5: Solve for x
    x = 134,451.91/312.76
  6. Step 6: Final answer
    x = 429.90

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.