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Finding the Fourth Proportional to 890.60, 1,229.20 and 558.80

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Solution

The fourth proportional to 890.60, 1,229.20 and 558.80 is: 771.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.60 : 1,229.20 = 558.80 : x
  2. Step 2: Convert to fraction form
    890.60/1,229.20 = 558.80/x
  3. Step 3: Cross multiply
    890.60x = 1,229.20 × 558.80
  4. Step 4: Simplify right side
    890.60x = 686,876.96
  5. Step 5: Solve for x
    x = 686,876.96/890.60
  6. Step 6: Final answer
    x = 771.25

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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.