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Finding the Fourth Proportional to 79.78, 110.14 and 74.31

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Solution

The fourth proportional to 79.78, 110.14 and 74.31 is: 102.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.78 : 110.14 = 74.31 : x
  2. Step 2: Convert to fraction form
    79.78/110.14 = 74.31/x
  3. Step 3: Cross multiply
    79.78x = 110.14 × 74.31
  4. Step 4: Simplify right side
    79.78x = 8,184.32
  5. Step 5: Solve for x
    x = 8,184.32/79.78
  6. Step 6: Final answer
    x = 102.59

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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.