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Finding the Fourth Proportional to 43.80, 65.61 and 31.79

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Solution

The fourth proportional to 43.80, 65.61 and 31.79 is: 47.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    43.80 : 65.61 = 31.79 : x
  2. Step 2: Convert to fraction form
    43.80/65.61 = 31.79/x
  3. Step 3: Cross multiply
    43.80x = 65.61 × 31.79
  4. Step 4: Simplify right side
    43.80x = 2,085.41
  5. Step 5: Solve for x
    x = 2,085.41/43.80
  6. Step 6: Final answer
    x = 47.61

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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.