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Finding the Fourth Proportional to 78.79, 118.19 and 30.70

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Solution

The fourth proportional to 78.79, 118.19 and 30.70 is: 46.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.79 : 118.19 = 30.70 : x
  2. Step 2: Convert to fraction form
    78.79/118.19 = 30.70/x
  3. Step 3: Cross multiply
    78.79x = 118.19 × 30.70
  4. Step 4: Simplify right side
    78.79x = 3,627.69
  5. Step 5: Solve for x
    x = 3,627.69/78.79
  6. Step 6: Final answer
    x = 46.05

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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.