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Finding the Fourth Proportional to 70.89, 105.60 and 66.75

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Solution

The fourth proportional to 70.89, 105.60 and 66.75 is: 99.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.89 : 105.60 = 66.75 : x
  2. Step 2: Convert to fraction form
    70.89/105.60 = 66.75/x
  3. Step 3: Cross multiply
    70.89x = 105.60 × 66.75
  4. Step 4: Simplify right side
    70.89x = 7,048.80
  5. Step 5: Solve for x
    x = 7,048.80/70.89
  6. Step 6: Final answer
    x = 99.43

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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.