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Finding the Fourth Proportional to 32.78, 45.20 and 21.71

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Solution

The fourth proportional to 32.78, 45.20 and 21.71 is: 29.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    32.78 : 45.20 = 21.71 : x
  2. Step 2: Convert to fraction form
    32.78/45.20 = 21.71/x
  3. Step 3: Cross multiply
    32.78x = 45.20 × 21.71
  4. Step 4: Simplify right side
    32.78x = 981.46
  5. Step 5: Solve for x
    x = 981.46/32.78
  6. Step 6: Final answer
    x = 29.94

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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.