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Finding the Fourth Proportional to 638.55, 957.86 and 205.71

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Solution

The fourth proportional to 638.55, 957.86 and 205.71 is: 308.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.55 : 957.86 = 205.71 : x
  2. Step 2: Convert to fraction form
    638.55/957.86 = 205.71/x
  3. Step 3: Cross multiply
    638.55x = 957.86 × 205.71
  4. Step 4: Simplify right side
    638.55x = 197,040.35
  5. Step 5: Solve for x
    x = 197,040.35/638.55
  6. Step 6: Final answer
    x = 308.57

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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.