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Finding the Fourth Proportional to 671.72, 999.60 and 645.80

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Solution

The fourth proportional to 671.72, 999.60 and 645.80 is: 961.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    671.72 : 999.60 = 645.80 : x
  2. Step 2: Convert to fraction form
    671.72/999.60 = 645.80/x
  3. Step 3: Cross multiply
    671.72x = 999.60 × 645.80
  4. Step 4: Simplify right side
    671.72x = 645,541.68
  5. Step 5: Solve for x
    x = 645,541.68/671.72
  6. Step 6: Final answer
    x = 961.03

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.