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Finding the Fourth Proportional to 431.06, 646.25 and 199.78

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Solution

The fourth proportional to 431.06, 646.25 and 199.78 is: 299.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.06 : 646.25 = 199.78 : x
  2. Step 2: Convert to fraction form
    431.06/646.25 = 199.78/x
  3. Step 3: Cross multiply
    431.06x = 646.25 × 199.78
  4. Step 4: Simplify right side
    431.06x = 129,107.83
  5. Step 5: Solve for x
    x = 129,107.83/431.06
  6. Step 6: Final answer
    x = 299.51

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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.