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Finding the Fourth Proportional to 39.15, 58.71 and 17.78

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Solution

The fourth proportional to 39.15, 58.71 and 17.78 is: 26.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.15 : 58.71 = 17.78 : x
  2. Step 2: Convert to fraction form
    39.15/58.71 = 17.78/x
  3. Step 3: Cross multiply
    39.15x = 58.71 × 17.78
  4. Step 4: Simplify right side
    39.15x = 1,043.57
  5. Step 5: Solve for x
    x = 1,043.57/39.15
  6. Step 6: Final answer
    x = 26.66

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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.