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Finding the Fourth Proportional to 79.80, 110.21 and 66.08

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Solution

The fourth proportional to 79.80, 110.21 and 66.08 is: 91.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.80 : 110.21 = 66.08 : x
  2. Step 2: Convert to fraction form
    79.80/110.21 = 66.08/x
  3. Step 3: Cross multiply
    79.80x = 110.21 × 66.08
  4. Step 4: Simplify right side
    79.80x = 7,281.80
  5. Step 5: Solve for x
    x = 7,281.80/79.80
  6. Step 6: Final answer
    x = 91.25

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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.