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Finding the Fourth Proportional to 427.55, 640.72 and 170.75

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Solution

The fourth proportional to 427.55, 640.72 and 170.75 is: 255.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.55 : 640.72 = 170.75 : x
  2. Step 2: Convert to fraction form
    427.55/640.72 = 170.75/x
  3. Step 3: Cross multiply
    427.55x = 640.72 × 170.75
  4. Step 4: Simplify right side
    427.55x = 109,402.94
  5. Step 5: Solve for x
    x = 109,402.94/427.55
  6. Step 6: Final answer
    x = 255.88

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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.