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Finding the Fourth Proportional to 79.31, 109.40 and 49.79

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Solution

The fourth proportional to 79.31, 109.40 and 49.79 is: 68.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.31 : 109.40 = 49.79 : x
  2. Step 2: Convert to fraction form
    79.31/109.40 = 49.79/x
  3. Step 3: Cross multiply
    79.31x = 109.40 × 49.79
  4. Step 4: Simplify right side
    79.31x = 5,446.23
  5. Step 5: Solve for x
    x = 5,446.23/79.31
  6. Step 6: Final answer
    x = 68.67

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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.