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Finding the Fourth Proportional to 419.15, 628.70 and 199.88

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Solution

The fourth proportional to 419.15, 628.70 and 199.88 is: 299.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.15 : 628.70 = 199.88 : x
  2. Step 2: Convert to fraction form
    419.15/628.70 = 199.88/x
  3. Step 3: Cross multiply
    419.15x = 628.70 × 199.88
  4. Step 4: Simplify right side
    419.15x = 125,660.41
  5. Step 5: Solve for x
    x = 125,660.41/419.15
  6. Step 6: Final answer
    x = 299.80

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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.