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Finding the Fourth Proportional to 428.78, 591.39 and 304.31

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Solution

The fourth proportional to 428.78, 591.39 and 304.31 is: 419.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.78 : 591.39 = 304.31 : x
  2. Step 2: Convert to fraction form
    428.78/591.39 = 304.31/x
  3. Step 3: Cross multiply
    428.78x = 591.39 × 304.31
  4. Step 4: Simplify right side
    428.78x = 179,965.89
  5. Step 5: Solve for x
    x = 179,965.89/428.78
  6. Step 6: Final answer
    x = 419.72

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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.