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Finding the Fourth Proportional to 72.98, 109.86 and 66.60

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Solution

The fourth proportional to 72.98, 109.86 and 66.60 is: 100.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.98 : 109.86 = 66.60 : x
  2. Step 2: Convert to fraction form
    72.98/109.86 = 66.60/x
  3. Step 3: Cross multiply
    72.98x = 109.86 × 66.60
  4. Step 4: Simplify right side
    72.98x = 7,316.68
  5. Step 5: Solve for x
    x = 7,316.68/72.98
  6. Step 6: Final answer
    x = 100.26

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.