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Finding the Fourth Proportional to 820.05, 1,229.81 and 409.08

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Solution

The fourth proportional to 820.05, 1,229.81 and 409.08 is: 613.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.05 : 1,229.81 = 409.08 : x
  2. Step 2: Convert to fraction form
    820.05/1,229.81 = 409.08/x
  3. Step 3: Cross multiply
    820.05x = 1,229.81 × 409.08
  4. Step 4: Simplify right side
    820.05x = 503,084.02
  5. Step 5: Solve for x
    x = 503,084.02/820.05
  6. Step 6: Final answer
    x = 613.48

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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.