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Finding the Fourth Proportional to 821.31, 1,230.51 and 560.47

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Solution

The fourth proportional to 821.31, 1,230.51 and 560.47 is: 839.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.31 : 1,230.51 = 560.47 : x
  2. Step 2: Convert to fraction form
    821.31/1,230.51 = 560.47/x
  3. Step 3: Cross multiply
    821.31x = 1,230.51 × 560.47
  4. Step 4: Simplify right side
    821.31x = 689,662.12
  5. Step 5: Solve for x
    x = 689,662.12/821.31
  6. Step 6: Final answer
    x = 839.71

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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.