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Finding the Fourth Proportional to 520.50, 780.75 and 315.30

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Solution

The fourth proportional to 520.50, 780.75 and 315.30 is: 472.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.50 : 780.75 = 315.30 : x
  2. Step 2: Convert to fraction form
    520.50/780.75 = 315.30/x
  3. Step 3: Cross multiply
    520.50x = 780.75 × 315.30
  4. Step 4: Simplify right side
    520.50x = 246,170.48
  5. Step 5: Solve for x
    x = 246,170.48/520.50
  6. Step 6: Final answer
    x = 472.95

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.