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Finding the Fourth Proportional to 820.84, 1,230.36 and 409.87

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Solution

The fourth proportional to 820.84, 1,230.36 and 409.87 is: 614.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.84 : 1,230.36 = 409.87 : x
  2. Step 2: Convert to fraction form
    820.84/1,230.36 = 409.87/x
  3. Step 3: Cross multiply
    820.84x = 1,230.36 × 409.87
  4. Step 4: Simplify right side
    820.84x = 504,287.65
  5. Step 5: Solve for x
    x = 504,287.65/820.84
  6. Step 6: Final answer
    x = 614.36

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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.