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Finding the Fourth Proportional to 79.54, 119.30 and 66.78

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Solution

The fourth proportional to 79.54, 119.30 and 66.78 is: 100.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.54 : 119.30 = 66.78 : x
  2. Step 2: Convert to fraction form
    79.54/119.30 = 66.78/x
  3. Step 3: Cross multiply
    79.54x = 119.30 × 66.78
  4. Step 4: Simplify right side
    79.54x = 7,967.02
  5. Step 5: Solve for x
    x = 7,967.02/79.54
  6. Step 6: Final answer
    x = 100.17

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.