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Finding the Fourth Proportional to 76.56, 105.57 and 64.95

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Solution

The fourth proportional to 76.56, 105.57 and 64.95 is: 89.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.56 : 105.57 = 64.95 : x
  2. Step 2: Convert to fraction form
    76.56/105.57 = 64.95/x
  3. Step 3: Cross multiply
    76.56x = 105.57 × 64.95
  4. Step 4: Simplify right side
    76.56x = 6,856.77
  5. Step 5: Solve for x
    x = 6,856.77/76.56
  6. Step 6: Final answer
    x = 89.56

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.