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Finding the Fourth Proportional to 21.07, 31.60 and 8.23

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Solution

The fourth proportional to 21.07, 31.60 and 8.23 is: 12.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.07 : 31.60 = 8.23 : x
  2. Step 2: Convert to fraction form
    21.07/31.60 = 8.23/x
  3. Step 3: Cross multiply
    21.07x = 31.60 × 8.23
  4. Step 4: Simplify right side
    21.07x = 259.97
  5. Step 5: Solve for x
    x = 259.97/21.07
  6. Step 6: Final answer
    x = 12.34

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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.