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Finding the Fourth Proportional to 72.16, 108.85 and 68.57

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Solution

The fourth proportional to 72.16, 108.85 and 68.57 is: 103.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.16 : 108.85 = 68.57 : x
  2. Step 2: Convert to fraction form
    72.16/108.85 = 68.57/x
  3. Step 3: Cross multiply
    72.16x = 108.85 × 68.57
  4. Step 4: Simplify right side
    72.16x = 7,463.84
  5. Step 5: Solve for x
    x = 7,463.84/72.16
  6. Step 6: Final answer
    x = 103.43

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.