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Finding the Fourth Proportional to 79.20, 118.81 and 30.45

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Solution

The fourth proportional to 79.20, 118.81 and 30.45 is: 45.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.20 : 118.81 = 30.45 : x
  2. Step 2: Convert to fraction form
    79.20/118.81 = 30.45/x
  3. Step 3: Cross multiply
    79.20x = 118.81 × 30.45
  4. Step 4: Simplify right side
    79.20x = 3,618.25
  5. Step 5: Solve for x
    x = 3,618.25/79.20
  6. Step 6: Final answer
    x = 45.68

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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.