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Finding the Fourth Proportional to 520.85, 780.80 and 247.20

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Solution

The fourth proportional to 520.85, 780.80 and 247.20 is: 370.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.85 : 780.80 = 247.20 : x
  2. Step 2: Convert to fraction form
    520.85/780.80 = 247.20/x
  3. Step 3: Cross multiply
    520.85x = 780.80 × 247.20
  4. Step 4: Simplify right side
    520.85x = 193,012.52
  5. Step 5: Solve for x
    x = 193,012.52/520.85
  6. Step 6: Final answer
    x = 370.58

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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.