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Finding the Fourth Proportional to 638.12, 957.21 and 199.40

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Solution

The fourth proportional to 638.12, 957.21 and 199.40 is: 299.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.12 : 957.21 = 199.40 : x
  2. Step 2: Convert to fraction form
    638.12/957.21 = 199.40/x
  3. Step 3: Cross multiply
    638.12x = 957.21 × 199.40
  4. Step 4: Simplify right side
    638.12x = 190,867.67
  5. Step 5: Solve for x
    x = 190,867.67/638.12
  6. Step 6: Final answer
    x = 299.11

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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.