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Finding the Fourth Proportional to 405.11, 607.68 and 131.21

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Solution

The fourth proportional to 405.11, 607.68 and 131.21 is: 196.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.11 : 607.68 = 131.21 : x
  2. Step 2: Convert to fraction form
    405.11/607.68 = 131.21/x
  3. Step 3: Cross multiply
    405.11x = 607.68 × 131.21
  4. Step 4: Simplify right side
    405.11x = 79,730.65
  5. Step 5: Solve for x
    x = 79,730.65/405.11
  6. Step 6: Final answer
    x = 196.81

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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.