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Finding the Fourth Proportional to 820.89, 1,230.86 and 561.29

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Solution

The fourth proportional to 820.89, 1,230.86 and 561.29 is: 841.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.89 : 1,230.86 = 561.29 : x
  2. Step 2: Convert to fraction form
    820.89/1,230.86 = 561.29/x
  3. Step 3: Cross multiply
    820.89x = 1,230.86 × 561.29
  4. Step 4: Simplify right side
    820.89x = 690,864.66
  5. Step 5: Solve for x
    x = 690,864.66/820.89
  6. Step 6: Final answer
    x = 841.60

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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.