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Finding the Fourth Proportional to 818.96, 1,228.61 and 385.88

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Solution

The fourth proportional to 818.96, 1,228.61 and 385.88 is: 578.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.96 : 1,228.61 = 385.88 : x
  2. Step 2: Convert to fraction form
    818.96/1,228.61 = 385.88/x
  3. Step 3: Cross multiply
    818.96x = 1,228.61 × 385.88
  4. Step 4: Simplify right side
    818.96x = 474,090.85
  5. Step 5: Solve for x
    x = 474,090.85/818.96
  6. Step 6: Final answer
    x = 578.90

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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.