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Finding the Fourth Proportional to 427.18, 640.39 and 170.86

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Solution

The fourth proportional to 427.18, 640.39 and 170.86 is: 256.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.18 : 640.39 = 170.86 : x
  2. Step 2: Convert to fraction form
    427.18/640.39 = 170.86/x
  3. Step 3: Cross multiply
    427.18x = 640.39 × 170.86
  4. Step 4: Simplify right side
    427.18x = 109,417.04
  5. Step 5: Solve for x
    x = 109,417.04/427.18
  6. Step 6: Final answer
    x = 256.14

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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.