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Finding the Fourth Proportional to 405.90, 608.78 and 113.42

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Solution

The fourth proportional to 405.90, 608.78 and 113.42 is: 170.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.90 : 608.78 = 113.42 : x
  2. Step 2: Convert to fraction form
    405.90/608.78 = 113.42/x
  3. Step 3: Cross multiply
    405.90x = 608.78 × 113.42
  4. Step 4: Simplify right side
    405.90x = 69,049.63
  5. Step 5: Solve for x
    x = 69,049.63/405.90
  6. Step 6: Final answer
    x = 170.11

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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.