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Finding the Fourth Proportional to 21.23, 31.85 and 17.47

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Solution

The fourth proportional to 21.23, 31.85 and 17.47 is: 26.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.23 : 31.85 = 17.47 : x
  2. Step 2: Convert to fraction form
    21.23/31.85 = 17.47/x
  3. Step 3: Cross multiply
    21.23x = 31.85 × 17.47
  4. Step 4: Simplify right side
    21.23x = 556.42
  5. Step 5: Solve for x
    x = 556.42/21.23
  6. Step 6: Final answer
    x = 26.21

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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.