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Finding the Fourth Proportional to 427.61, 641.49 and 135.15

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Solution

The fourth proportional to 427.61, 641.49 and 135.15 is: 202.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.61 : 641.49 = 135.15 : x
  2. Step 2: Convert to fraction form
    427.61/641.49 = 135.15/x
  3. Step 3: Cross multiply
    427.61x = 641.49 × 135.15
  4. Step 4: Simplify right side
    427.61x = 86,699.02
  5. Step 5: Solve for x
    x = 86,699.02/427.61
  6. Step 6: Final answer
    x = 202.75

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.