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Finding the Fourth Proportional to 428.78, 591.50 and 288.94

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Solution

The fourth proportional to 428.78, 591.50 and 288.94 is: 398.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.78 : 591.50 = 288.94 : x
  2. Step 2: Convert to fraction form
    428.78/591.50 = 288.94/x
  3. Step 3: Cross multiply
    428.78x = 591.50 × 288.94
  4. Step 4: Simplify right side
    428.78x = 170,908.01
  5. Step 5: Solve for x
    x = 170,908.01/428.78
  6. Step 6: Final answer
    x = 398.59

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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.