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Finding the Fourth Proportional to 667.79, 920.06 and 490.40

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Solution

The fourth proportional to 667.79, 920.06 and 490.40 is: 675.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.79 : 920.06 = 490.40 : x
  2. Step 2: Convert to fraction form
    667.79/920.06 = 490.40/x
  3. Step 3: Cross multiply
    667.79x = 920.06 × 490.40
  4. Step 4: Simplify right side
    667.79x = 451,200.84
  5. Step 5: Solve for x
    x = 451,200.84/667.79
  6. Step 6: Final answer
    x = 675.66

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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.