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Finding the Fourth Proportional to 428.31, 591.30 and 288.45

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Solution

The fourth proportional to 428.31, 591.30 and 288.45 is: 398.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.31 : 591.30 = 288.45 : x
  2. Step 2: Convert to fraction form
    428.31/591.30 = 288.45/x
  3. Step 3: Cross multiply
    428.31x = 591.30 × 288.45
  4. Step 4: Simplify right side
    428.31x = 170,560.49
  5. Step 5: Solve for x
    x = 170,560.49/428.31
  6. Step 6: Final answer
    x = 398.22

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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.