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Finding the Fourth Proportional to 428.90, 641.83 and 266.66

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Solution

The fourth proportional to 428.90, 641.83 and 266.66 is: 399.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.90 : 641.83 = 266.66 : x
  2. Step 2: Convert to fraction form
    428.90/641.83 = 266.66/x
  3. Step 3: Cross multiply
    428.90x = 641.83 × 266.66
  4. Step 4: Simplify right side
    428.90x = 171,150.39
  5. Step 5: Solve for x
    x = 171,150.39/428.90
  6. Step 6: Final answer
    x = 399.04

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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.