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Finding the Fourth Proportional to 405.31, 607.89 and 199.81

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Solution

The fourth proportional to 405.31, 607.89 and 199.81 is: 299.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.31 : 607.89 = 199.81 : x
  2. Step 2: Convert to fraction form
    405.31/607.89 = 199.81/x
  3. Step 3: Cross multiply
    405.31x = 607.89 × 199.81
  4. Step 4: Simplify right side
    405.31x = 121,460.98
  5. Step 5: Solve for x
    x = 121,460.98/405.31
  6. Step 6: Final answer
    x = 299.68

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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.