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Finding the Fourth Proportional to 890.55, 1,229.04 and 641.88

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Solution

The fourth proportional to 890.55, 1,229.04 and 641.88 is: 885.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.55 : 1,229.04 = 641.88 : x
  2. Step 2: Convert to fraction form
    890.55/1,229.04 = 641.88/x
  3. Step 3: Cross multiply
    890.55x = 1,229.04 × 641.88
  4. Step 4: Simplify right side
    890.55x = 788,896.20
  5. Step 5: Solve for x
    x = 788,896.20/890.55
  6. Step 6: Final answer
    x = 885.85

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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.