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Finding the Fourth Proportional to 79, 108.38 and 76.70

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Solution

The fourth proportional to 79, 108.38 and 76.70 is: 105.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    79 : 108.38 = 76.70 : x
  2. Step 2: Convert to fraction form
    79/108.38 = 76.70/x
  3. Step 3: Cross multiply
    79x = 108.38 × 76.70
  4. Step 4: Simplify right side
    79x = 8,312.75
  5. Step 5: Solve for x
    x = 8,312.75/79
  6. Step 6: Final answer
    x = 105.22

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.