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Finding the Fourth Proportional to 821.47, 1,235.04 and 660.28

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Solution

The fourth proportional to 821.47, 1,235.04 and 660.28 is: 992.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.47 : 1,235.04 = 660.28 : x
  2. Step 2: Convert to fraction form
    821.47/1,235.04 = 660.28/x
  3. Step 3: Cross multiply
    821.47x = 1,235.04 × 660.28
  4. Step 4: Simplify right side
    821.47x = 815,466.04
  5. Step 5: Solve for x
    x = 815,466.04/821.47
  6. Step 6: Final answer
    x = 992.70

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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.