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Finding the Fourth Proportional to 138.96, 208.05 and 70.34

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Solution

The fourth proportional to 138.96, 208.05 and 70.34 is: 105.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.96 : 208.05 = 70.34 : x
  2. Step 2: Convert to fraction form
    138.96/208.05 = 70.34/x
  3. Step 3: Cross multiply
    138.96x = 208.05 × 70.34
  4. Step 4: Simplify right side
    138.96x = 14,633.33
  5. Step 5: Solve for x
    x = 14,633.33/138.96
  6. Step 6: Final answer
    x = 105.31

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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.