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Finding the Fourth Proportional to 428.22, 642.20 and 274.32

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Solution

The fourth proportional to 428.22, 642.20 and 274.32 is: 411.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.22 : 642.20 = 274.32 : x
  2. Step 2: Convert to fraction form
    428.22/642.20 = 274.32/x
  3. Step 3: Cross multiply
    428.22x = 642.20 × 274.32
  4. Step 4: Simplify right side
    428.22x = 176,166.93
  5. Step 5: Solve for x
    x = 176,166.93/428.22
  6. Step 6: Final answer
    x = 411.39

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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.