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Finding the Fourth Proportional to 107.70, 148.44 and 78.21

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Solution

The fourth proportional to 107.70, 148.44 and 78.21 is: 107.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    107.70 : 148.44 = 78.21 : x
  2. Step 2: Convert to fraction form
    107.70/148.44 = 78.21/x
  3. Step 3: Cross multiply
    107.70x = 148.44 × 78.21
  4. Step 4: Simplify right side
    107.70x = 11,609.49
  5. Step 5: Solve for x
    x = 11,609.49/107.70
  6. Step 6: Final answer
    x = 107.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.