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Finding the Fourth Proportional to 515.76, 711.80 and 308.76

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Solution

The fourth proportional to 515.76, 711.80 and 308.76 is: 426.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.76 : 711.80 = 308.76 : x
  2. Step 2: Convert to fraction form
    515.76/711.80 = 308.76/x
  3. Step 3: Cross multiply
    515.76x = 711.80 × 308.76
  4. Step 4: Simplify right side
    515.76x = 219,775.37
  5. Step 5: Solve for x
    x = 219,775.37/515.76
  6. Step 6: Final answer
    x = 426.12

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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.