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Finding the Fourth Proportional to 428.67, 643.11 and 185.13

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Solution

The fourth proportional to 428.67, 643.11 and 185.13 is: 277.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.67 : 643.11 = 185.13 : x
  2. Step 2: Convert to fraction form
    428.67/643.11 = 185.13/x
  3. Step 3: Cross multiply
    428.67x = 643.11 × 185.13
  4. Step 4: Simplify right side
    428.67x = 119,058.95
  5. Step 5: Solve for x
    x = 119,058.95/428.67
  6. Step 6: Final answer
    x = 277.74

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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.