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Finding the Fourth Proportional to 428.13, 590.40 and 317.88

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Solution

The fourth proportional to 428.13, 590.40 and 317.88 is: 438.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.13 : 590.40 = 317.88 : x
  2. Step 2: Convert to fraction form
    428.13/590.40 = 317.88/x
  3. Step 3: Cross multiply
    428.13x = 590.40 × 317.88
  4. Step 4: Simplify right side
    428.13x = 187,676.35
  5. Step 5: Solve for x
    x = 187,676.35/428.13
  6. Step 6: Final answer
    x = 438.36

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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.