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Finding the Fourth Proportional to 405.79, 608.70 and 131.80

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Solution

The fourth proportional to 405.79, 608.70 and 131.80 is: 197.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.79 : 608.70 = 131.80 : x
  2. Step 2: Convert to fraction form
    405.79/608.70 = 131.80/x
  3. Step 3: Cross multiply
    405.79x = 608.70 × 131.80
  4. Step 4: Simplify right side
    405.79x = 80,226.66
  5. Step 5: Solve for x
    x = 80,226.66/405.79
  6. Step 6: Final answer
    x = 197.70

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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.