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Finding the Fourth Proportional to 39.79, 59.70 and 21.77

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Solution

The fourth proportional to 39.79, 59.70 and 21.77 is: 32.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.79 : 59.70 = 21.77 : x
  2. Step 2: Convert to fraction form
    39.79/59.70 = 21.77/x
  3. Step 3: Cross multiply
    39.79x = 59.70 × 21.77
  4. Step 4: Simplify right side
    39.79x = 1,299.68
  5. Step 5: Solve for x
    x = 1,299.68/39.79
  6. Step 6: Final answer
    x = 32.66

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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.