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Finding the Fourth Proportional to 43.81, 65.65 and 20.99

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Solution

The fourth proportional to 43.81, 65.65 and 20.99 is: 31.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    43.81 : 65.65 = 20.99 : x
  2. Step 2: Convert to fraction form
    43.81/65.65 = 20.99/x
  3. Step 3: Cross multiply
    43.81x = 65.65 × 20.99
  4. Step 4: Simplify right side
    43.81x = 1,377.99
  5. Step 5: Solve for x
    x = 1,377.99/43.81
  6. Step 6: Final answer
    x = 31.45

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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.