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Finding the Fourth Proportional to 70.85, 105.72 and 68.51

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Solution

The fourth proportional to 70.85, 105.72 and 68.51 is: 102.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.85 : 105.72 = 68.51 : x
  2. Step 2: Convert to fraction form
    70.85/105.72 = 68.51/x
  3. Step 3: Cross multiply
    70.85x = 105.72 × 68.51
  4. Step 4: Simplify right side
    70.85x = 7,242.35
  5. Step 5: Solve for x
    x = 7,242.35/70.85
  6. Step 6: Final answer
    x = 102.23

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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.