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Finding the Fourth Proportional to 520.40, 780.60 and 490.70

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Solution

The fourth proportional to 520.40, 780.60 and 490.70 is: 736.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.40 : 780.60 = 490.70 : x
  2. Step 2: Convert to fraction form
    520.40/780.60 = 490.70/x
  3. Step 3: Cross multiply
    520.40x = 780.60 × 490.70
  4. Step 4: Simplify right side
    520.40x = 383,040.42
  5. Step 5: Solve for x
    x = 383,040.42/520.40
  6. Step 6: Final answer
    x = 736.05

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Similar ratio
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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.