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Finding the Fourth Proportional to 428.37, 642.05 and 197.07

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Solution

The fourth proportional to 428.37, 642.05 and 197.07 is: 295.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.37 : 642.05 = 197.07 : x
  2. Step 2: Convert to fraction form
    428.37/642.05 = 197.07/x
  3. Step 3: Cross multiply
    428.37x = 642.05 × 197.07
  4. Step 4: Simplify right side
    428.37x = 126,527.81
  5. Step 5: Solve for x
    x = 126,527.81/428.37
  6. Step 6: Final answer
    x = 295.37

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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.