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Finding the Fourth Proportional to 70.65, 105.12 and 68.49

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Solution

The fourth proportional to 70.65, 105.12 and 68.49 is: 101.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.65 : 105.12 = 68.49 : x
  2. Step 2: Convert to fraction form
    70.65/105.12 = 68.49/x
  3. Step 3: Cross multiply
    70.65x = 105.12 × 68.49
  4. Step 4: Simplify right side
    70.65x = 7,199.67
  5. Step 5: Solve for x
    x = 7,199.67/70.65
  6. Step 6: Final answer
    x = 101.91

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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.