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Finding the Fourth Proportional to 427.21, 640.89 and 153.25

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Solution

The fourth proportional to 427.21, 640.89 and 153.25 is: 229.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.21 : 640.89 = 153.25 : x
  2. Step 2: Convert to fraction form
    427.21/640.89 = 153.25/x
  3. Step 3: Cross multiply
    427.21x = 640.89 × 153.25
  4. Step 4: Simplify right side
    427.21x = 98,214.79
  5. Step 5: Solve for x
    x = 98,214.79/427.21
  6. Step 6: Final answer
    x = 229.90

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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.