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Finding the Fourth Proportional to 641.80, 885.36 and 421.12

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Solution

The fourth proportional to 641.80, 885.36 and 421.12 is: 580.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.80 : 885.36 = 421.12 : x
  2. Step 2: Convert to fraction form
    641.80/885.36 = 421.12/x
  3. Step 3: Cross multiply
    641.80x = 885.36 × 421.12
  4. Step 4: Simplify right side
    641.80x = 372,842.80
  5. Step 5: Solve for x
    x = 372,842.80/641.80
  6. Step 6: Final answer
    x = 580.93

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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.