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Finding the Fourth Proportional to 828.21, 1,142.88 and 478.89

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Solution

The fourth proportional to 828.21, 1,142.88 and 478.89 is: 660.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.21 : 1,142.88 = 478.89 : x
  2. Step 2: Convert to fraction form
    828.21/1,142.88 = 478.89/x
  3. Step 3: Cross multiply
    828.21x = 1,142.88 × 478.89
  4. Step 4: Simplify right side
    828.21x = 547,313.80
  5. Step 5: Solve for x
    x = 547,313.80/828.21
  6. Step 6: Final answer
    x = 660.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.