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Finding the Fourth Proportional to 69.16, 103.75 and 21.07

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Solution

The fourth proportional to 69.16, 103.75 and 21.07 is: 31.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.16 : 103.75 = 21.07 : x
  2. Step 2: Convert to fraction form
    69.16/103.75 = 21.07/x
  3. Step 3: Cross multiply
    69.16x = 103.75 × 21.07
  4. Step 4: Simplify right side
    69.16x = 2,186.01
  5. Step 5: Solve for x
    x = 2,186.01/69.16
  6. Step 6: Final answer
    x = 31.61

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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.