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Finding the Fourth Proportional to 427.78, 641.68 and 153.90

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Solution

The fourth proportional to 427.78, 641.68 and 153.90 is: 230.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.78 : 641.68 = 153.90 : x
  2. Step 2: Convert to fraction form
    427.78/641.68 = 153.90/x
  3. Step 3: Cross multiply
    427.78x = 641.68 × 153.90
  4. Step 4: Simplify right side
    427.78x = 98,751.76
  5. Step 5: Solve for x
    x = 98,751.76/427.78
  6. Step 6: Final answer
    x = 230.85

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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.