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Finding the Fourth Proportional to 28.70, 39.30 and 28.61

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Solution

The fourth proportional to 28.70, 39.30 and 28.61 is: 39.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.70 : 39.30 = 28.61 : x
  2. Step 2: Convert to fraction form
    28.70/39.30 = 28.61/x
  3. Step 3: Cross multiply
    28.70x = 39.30 × 28.61
  4. Step 4: Simplify right side
    28.70x = 1,124.36
  5. Step 5: Solve for x
    x = 1,124.36/28.70
  6. Step 6: Final answer
    x = 39.18

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.