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Finding the Fourth Proportional to 79.79, 119.70 and 28.42

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Solution

The fourth proportional to 79.79, 119.70 and 28.42 is: 42.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.79 : 119.70 = 28.42 : x
  2. Step 2: Convert to fraction form
    79.79/119.70 = 28.42/x
  3. Step 3: Cross multiply
    79.79x = 119.70 × 28.42
  4. Step 4: Simplify right side
    79.79x = 3,401.87
  5. Step 5: Solve for x
    x = 3,401.87/79.79
  6. Step 6: Final answer
    x = 42.64

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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.