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Finding the Fourth Proportional to 72.71, 109.59 and 68.80

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Solution

The fourth proportional to 72.71, 109.59 and 68.80 is: 103.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.71 : 109.59 = 68.80 : x
  2. Step 2: Convert to fraction form
    72.71/109.59 = 68.80/x
  3. Step 3: Cross multiply
    72.71x = 109.59 × 68.80
  4. Step 4: Simplify right side
    72.71x = 7,539.79
  5. Step 5: Solve for x
    x = 7,539.79/72.71
  6. Step 6: Final answer
    x = 103.70

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.