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Finding the Fourth Proportional to 377.69, 519.95 and 311.40

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Solution

The fourth proportional to 377.69, 519.95 and 311.40 is: 428.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    377.69 : 519.95 = 311.40 : x
  2. Step 2: Convert to fraction form
    377.69/519.95 = 311.40/x
  3. Step 3: Cross multiply
    377.69x = 519.95 × 311.40
  4. Step 4: Simplify right side
    377.69x = 161,913.21
  5. Step 5: Solve for x
    x = 161,913.21/377.69
  6. Step 6: Final answer
    x = 428.70

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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.