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Finding the Fourth Proportional to 70.31, 104.99 and 66.80

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Solution

The fourth proportional to 70.31, 104.99 and 66.80 is: 99.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.31 : 104.99 = 66.80 : x
  2. Step 2: Convert to fraction form
    70.31/104.99 = 66.80/x
  3. Step 3: Cross multiply
    70.31x = 104.99 × 66.80
  4. Step 4: Simplify right side
    70.31x = 7,013.26
  5. Step 5: Solve for x
    x = 7,013.26/70.31
  6. Step 6: Final answer
    x = 99.74

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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.