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Finding the Fourth Proportional to 520.85, 779.45 and 411.50

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Solution

The fourth proportional to 520.85, 779.45 and 411.50 is: 615.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.85 : 779.45 = 411.50 : x
  2. Step 2: Convert to fraction form
    520.85/779.45 = 411.50/x
  3. Step 3: Cross multiply
    520.85x = 779.45 × 411.50
  4. Step 4: Simplify right side
    520.85x = 320,741.62
  5. Step 5: Solve for x
    x = 320,741.62/520.85
  6. Step 6: Final answer
    x = 615.80

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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.