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Finding the Fourth Proportional to 72.81, 109.15 and 56.68

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Solution

The fourth proportional to 72.81, 109.15 and 56.68 is: 84.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.81 : 109.15 = 56.68 : x
  2. Step 2: Convert to fraction form
    72.81/109.15 = 56.68/x
  3. Step 3: Cross multiply
    72.81x = 109.15 × 56.68
  4. Step 4: Simplify right side
    72.81x = 6,186.62
  5. Step 5: Solve for x
    x = 6,186.62/72.81
  6. Step 6: Final answer
    x = 84.97

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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.