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Finding the Fourth Proportional to 428.39, 589.89 and 393.31

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Solution

The fourth proportional to 428.39, 589.89 and 393.31 is: 541.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.39 : 589.89 = 393.31 : x
  2. Step 2: Convert to fraction form
    428.39/589.89 = 393.31/x
  3. Step 3: Cross multiply
    428.39x = 589.89 × 393.31
  4. Step 4: Simplify right side
    428.39x = 232,009.64
  5. Step 5: Solve for x
    x = 232,009.64/428.39
  6. Step 6: Final answer
    x = 541.59

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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.