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Finding the Fourth Proportional to 821.78, 1,134.08 and 490.26

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Solution

The fourth proportional to 821.78, 1,134.08 and 490.26 is: 676.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.78 : 1,134.08 = 490.26 : x
  2. Step 2: Convert to fraction form
    821.78/1,134.08 = 490.26/x
  3. Step 3: Cross multiply
    821.78x = 1,134.08 × 490.26
  4. Step 4: Simplify right side
    821.78x = 555,994.06
  5. Step 5: Solve for x
    x = 555,994.06/821.78
  6. Step 6: Final answer
    x = 676.57

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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.