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Finding the Fourth Proportional to 138.48, 191.16 and 89.40

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Solution

The fourth proportional to 138.48, 191.16 and 89.40 is: 123.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.48 : 191.16 = 89.40 : x
  2. Step 2: Convert to fraction form
    138.48/191.16 = 89.40/x
  3. Step 3: Cross multiply
    138.48x = 191.16 × 89.40
  4. Step 4: Simplify right side
    138.48x = 17,089.70
  5. Step 5: Solve for x
    x = 17,089.70/138.48
  6. Step 6: Final answer
    x = 123.41

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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.