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Finding the Fourth Proportional to 69.51, 104.28 and 21.42

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Solution

The fourth proportional to 69.51, 104.28 and 21.42 is: 32.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.51 : 104.28 = 21.42 : x
  2. Step 2: Convert to fraction form
    69.51/104.28 = 21.42/x
  3. Step 3: Cross multiply
    69.51x = 104.28 × 21.42
  4. Step 4: Simplify right side
    69.51x = 2,233.68
  5. Step 5: Solve for x
    x = 2,233.68/69.51
  6. Step 6: Final answer
    x = 32.13

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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.