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Finding the Fourth Proportional to 820.57, 1,231.62 and 513

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Solution

The fourth proportional to 820.57, 1,231.62 and 513 is: 769.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.57 : 1,231.62 = 513 : x
  2. Step 2: Convert to fraction form
    820.57/1,231.62 = 513/x
  3. Step 3: Cross multiply
    820.57x = 1,231.62 × 513
  4. Step 4: Simplify right side
    820.57x = 631,821.06
  5. Step 5: Solve for x
    x = 631,821.06/820.57
  6. Step 6: Final answer
    x = 769.98

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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.