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Finding the Fourth Proportional to 70.79, 105.57 and 64.89

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Solution

The fourth proportional to 70.79, 105.57 and 64.89 is: 96.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.79 : 105.57 = 64.89 : x
  2. Step 2: Convert to fraction form
    70.79/105.57 = 64.89/x
  3. Step 3: Cross multiply
    70.79x = 105.57 × 64.89
  4. Step 4: Simplify right side
    70.79x = 6,850.44
  5. Step 5: Solve for x
    x = 6,850.44/70.79
  6. Step 6: Final answer
    x = 96.78

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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.