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Finding the Fourth Proportional to 145.70, 218.61 and 72.61

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Solution

The fourth proportional to 145.70, 218.61 and 72.61 is: 108.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.70 : 218.61 = 72.61 : x
  2. Step 2: Convert to fraction form
    145.70/218.61 = 72.61/x
  3. Step 3: Cross multiply
    145.70x = 218.61 × 72.61
  4. Step 4: Simplify right side
    145.70x = 15,872.73
  5. Step 5: Solve for x
    x = 15,872.73/145.70
  6. Step 6: Final answer
    x = 108.94

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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.