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Finding the Fourth Proportional to 642.98, 963.05 and 520.67

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Solution

The fourth proportional to 642.98, 963.05 and 520.67 is: 779.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.98 : 963.05 = 520.67 : x
  2. Step 2: Convert to fraction form
    642.98/963.05 = 520.67/x
  3. Step 3: Cross multiply
    642.98x = 963.05 × 520.67
  4. Step 4: Simplify right side
    642.98x = 501,423.82
  5. Step 5: Solve for x
    x = 501,423.82/642.98
  6. Step 6: Final answer
    x = 779.85

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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.