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Finding the Fourth Proportional to 153.79, 230.41 and 81.70

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Solution

The fourth proportional to 153.79, 230.41 and 81.70 is: 122.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.79 : 230.41 = 81.70 : x
  2. Step 2: Convert to fraction form
    153.79/230.41 = 81.70/x
  3. Step 3: Cross multiply
    153.79x = 230.41 × 81.70
  4. Step 4: Simplify right side
    153.79x = 18,824.50
  5. Step 5: Solve for x
    x = 18,824.50/153.79
  6. Step 6: Final answer
    x = 122.40

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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.