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Finding the Fourth Proportional to 818.81, 1,229.12 and 407.84

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Solution

The fourth proportional to 818.81, 1,229.12 and 407.84 is: 612.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.81 : 1,229.12 = 407.84 : x
  2. Step 2: Convert to fraction form
    818.81/1,229.12 = 407.84/x
  3. Step 3: Cross multiply
    818.81x = 1,229.12 × 407.84
  4. Step 4: Simplify right side
    818.81x = 501,276.12
  5. Step 5: Solve for x
    x = 501,276.12/818.81
  6. Step 6: Final answer
    x = 612.20

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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.