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Finding the Fourth Proportional to 428.03, 641.58 and 290.73

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Solution

The fourth proportional to 428.03, 641.58 and 290.73 is: 435.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.03 : 641.58 = 290.73 : x
  2. Step 2: Convert to fraction form
    428.03/641.58 = 290.73/x
  3. Step 3: Cross multiply
    428.03x = 641.58 × 290.73
  4. Step 4: Simplify right side
    428.03x = 186,526.55
  5. Step 5: Solve for x
    x = 186,526.55/428.03
  6. Step 6: Final answer
    x = 435.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.