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Finding the Fourth Proportional to 428.39, 591.33 and 288.90

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Solution

The fourth proportional to 428.39, 591.33 and 288.90 is: 398.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.39 : 591.33 = 288.90 : x
  2. Step 2: Convert to fraction form
    428.39/591.33 = 288.90/x
  3. Step 3: Cross multiply
    428.39x = 591.33 × 288.90
  4. Step 4: Simplify right side
    428.39x = 170,835.24
  5. Step 5: Solve for x
    x = 170,835.24/428.39
  6. Step 6: Final answer
    x = 398.79

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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.