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Finding the Fourth Proportional to 515.50, 711.57 and 308.50

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Solution

The fourth proportional to 515.50, 711.57 and 308.50 is: 425.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.50 : 711.57 = 308.50 : x
  2. Step 2: Convert to fraction form
    515.50/711.57 = 308.50/x
  3. Step 3: Cross multiply
    515.50x = 711.57 × 308.50
  4. Step 4: Simplify right side
    515.50x = 219,519.35
  5. Step 5: Solve for x
    x = 219,519.35/515.50
  6. Step 6: Final answer
    x = 425.84

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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.