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Finding the Fourth Proportional to 72.80, 109.16 and 36.64

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Solution

The fourth proportional to 72.80, 109.16 and 36.64 is: 54.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.80 : 109.16 = 36.64 : x
  2. Step 2: Convert to fraction form
    72.80/109.16 = 36.64/x
  3. Step 3: Cross multiply
    72.80x = 109.16 × 36.64
  4. Step 4: Simplify right side
    72.80x = 3,999.62
  5. Step 5: Solve for x
    x = 3,999.62/72.80
  6. Step 6: Final answer
    x = 54.94

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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.