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Finding the Fourth Proportional to 72.80, 109.16 and 54.34

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Solution

The fourth proportional to 72.80, 109.16 and 54.34 is: 81.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.80 : 109.16 = 54.34 : x
  2. Step 2: Convert to fraction form
    72.80/109.16 = 54.34/x
  3. Step 3: Cross multiply
    72.80x = 109.16 × 54.34
  4. Step 4: Simplify right side
    72.80x = 5,931.75
  5. Step 5: Solve for x
    x = 5,931.75/72.80
  6. Step 6: Final answer
    x = 81.48

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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.