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Finding the Fourth Proportional to 27.89, 38.40 and 21.67

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Solution

The fourth proportional to 27.89, 38.40 and 21.67 is: 29.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.89 : 38.40 = 21.67 : x
  2. Step 2: Convert to fraction form
    27.89/38.40 = 21.67/x
  3. Step 3: Cross multiply
    27.89x = 38.40 × 21.67
  4. Step 4: Simplify right side
    27.89x = 831.83
  5. Step 5: Solve for x
    x = 831.83/27.89
  6. Step 6: Final answer
    x = 29.83

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.