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Finding the Fourth Proportional to 72.87, 108.78 and 64.77

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Solution

The fourth proportional to 72.87, 108.78 and 64.77 is: 96.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.87 : 108.78 = 64.77 : x
  2. Step 2: Convert to fraction form
    72.87/108.78 = 64.77/x
  3. Step 3: Cross multiply
    72.87x = 108.78 × 64.77
  4. Step 4: Simplify right side
    72.87x = 7,045.30
  5. Step 5: Solve for x
    x = 7,045.30/72.87
  6. Step 6: Final answer
    x = 96.69

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.