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Finding the Fourth Proportional to 79.73, 109.78 and 71.63

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Solution

The fourth proportional to 79.73, 109.78 and 71.63 is: 98.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.73 : 109.78 = 71.63 : x
  2. Step 2: Convert to fraction form
    79.73/109.78 = 71.63/x
  3. Step 3: Cross multiply
    79.73x = 109.78 × 71.63
  4. Step 4: Simplify right side
    79.73x = 7,862.81
  5. Step 5: Solve for x
    x = 7,862.81/79.73
  6. Step 6: Final answer
    x = 98.62

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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.