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Finding the Fourth Proportional to 21.55, 32.10 and 21.29

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Solution

The fourth proportional to 21.55, 32.10 and 21.29 is: 31.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.55 : 32.10 = 21.29 : x
  2. Step 2: Convert to fraction form
    21.55/32.10 = 21.29/x
  3. Step 3: Cross multiply
    21.55x = 32.10 × 21.29
  4. Step 4: Simplify right side
    21.55x = 683.41
  5. Step 5: Solve for x
    x = 683.41/21.55
  6. Step 6: Final answer
    x = 31.71

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.