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Finding the Fourth Proportional to 861.40, 1,188.66 and 488.43

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Solution

The fourth proportional to 861.40, 1,188.66 and 488.43 is: 673.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.40 : 1,188.66 = 488.43 : x
  2. Step 2: Convert to fraction form
    861.40/1,188.66 = 488.43/x
  3. Step 3: Cross multiply
    861.40x = 1,188.66 × 488.43
  4. Step 4: Simplify right side
    861.40x = 580,577.20
  5. Step 5: Solve for x
    x = 580,577.20/861.40
  6. Step 6: Final answer
    x = 673.99

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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.