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Finding the Fourth Proportional to 638.47, 957.69 and 199.72

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Solution

The fourth proportional to 638.47, 957.69 and 199.72 is: 299.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.47 : 957.69 = 199.72 : x
  2. Step 2: Convert to fraction form
    638.47/957.69 = 199.72/x
  3. Step 3: Cross multiply
    638.47x = 957.69 × 199.72
  4. Step 4: Simplify right side
    638.47x = 191,269.85
  5. Step 5: Solve for x
    x = 191,269.85/638.47
  6. Step 6: Final answer
    x = 299.58

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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.