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Finding the Fourth Proportional to 521.90, 719.78 and 490.58

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Solution

The fourth proportional to 521.90, 719.78 and 490.58 is: 676.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.90 : 719.78 = 490.58 : x
  2. Step 2: Convert to fraction form
    521.90/719.78 = 490.58/x
  3. Step 3: Cross multiply
    521.90x = 719.78 × 490.58
  4. Step 4: Simplify right side
    521.90x = 353,109.67
  5. Step 5: Solve for x
    x = 353,109.67/521.90
  6. Step 6: Final answer
    x = 676.58

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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.