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Finding the Fourth Proportional to 428.61, 591.43 and 288.70

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Solution

The fourth proportional to 428.61, 591.43 and 288.70 is: 398.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.61 : 591.43 = 288.70 : x
  2. Step 2: Convert to fraction form
    428.61/591.43 = 288.70/x
  3. Step 3: Cross multiply
    428.61x = 591.43 × 288.70
  4. Step 4: Simplify right side
    428.61x = 170,745.84
  5. Step 5: Solve for x
    x = 170,745.84/428.61
  6. Step 6: Final answer
    x = 398.37

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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.