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Finding the Fourth Proportional to 79.28, 118.94 and 78.09

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Solution

The fourth proportional to 79.28, 118.94 and 78.09 is: 117.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.28 : 118.94 = 78.09 : x
  2. Step 2: Convert to fraction form
    79.28/118.94 = 78.09/x
  3. Step 3: Cross multiply
    79.28x = 118.94 × 78.09
  4. Step 4: Simplify right side
    79.28x = 9,288.18
  5. Step 5: Solve for x
    x = 9,288.18/79.28
  6. Step 6: Final answer
    x = 117.16

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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.