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Finding the Fourth Proportional to 79.97, 110.21 and 66.15

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Solution

The fourth proportional to 79.97, 110.21 and 66.15 is: 91.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.97 : 110.21 = 66.15 : x
  2. Step 2: Convert to fraction form
    79.97/110.21 = 66.15/x
  3. Step 3: Cross multiply
    79.97x = 110.21 × 66.15
  4. Step 4: Simplify right side
    79.97x = 7,290.06
  5. Step 5: Solve for x
    x = 7,290.06/79.97
  6. Step 6: Final answer
    x = 91.17

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.