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Finding the Fourth Proportional to 820.81, 1,230.87 and 409.46

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Solution

The fourth proportional to 820.81, 1,230.87 and 409.46 is: 614.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.81 : 1,230.87 = 409.46 : x
  2. Step 2: Convert to fraction form
    820.81/1,230.87 = 409.46/x
  3. Step 3: Cross multiply
    820.81x = 1,230.87 × 409.46
  4. Step 4: Simplify right side
    820.81x = 503,986.26
  5. Step 5: Solve for x
    x = 503,986.26/820.81
  6. Step 6: Final answer
    x = 614.01

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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.