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Finding the Fourth Proportional to 431.09, 646.39 and 199.85

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Solution

The fourth proportional to 431.09, 646.39 and 199.85 is: 299.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.09 : 646.39 = 199.85 : x
  2. Step 2: Convert to fraction form
    431.09/646.39 = 199.85/x
  3. Step 3: Cross multiply
    431.09x = 646.39 × 199.85
  4. Step 4: Simplify right side
    431.09x = 129,179.43
  5. Step 5: Solve for x
    x = 129,179.43/431.09
  6. Step 6: Final answer
    x = 299.66

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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.