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Finding the Fourth Proportional to 419.20, 628.78 and 111.06

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Solution

The fourth proportional to 419.20, 628.78 and 111.06 is: 166.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.20 : 628.78 = 111.06 : x
  2. Step 2: Convert to fraction form
    419.20/628.78 = 111.06/x
  3. Step 3: Cross multiply
    419.20x = 628.78 × 111.06
  4. Step 4: Simplify right side
    419.20x = 69,833.60
  5. Step 5: Solve for x
    x = 69,833.60/419.20
  6. Step 6: Final answer
    x = 166.59

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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.