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Finding the Fourth Proportional to 72.28, 99.75 and 39.54

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Solution

The fourth proportional to 72.28, 99.75 and 39.54 is: 54.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.28 : 99.75 = 39.54 : x
  2. Step 2: Convert to fraction form
    72.28/99.75 = 39.54/x
  3. Step 3: Cross multiply
    72.28x = 99.75 × 39.54
  4. Step 4: Simplify right side
    72.28x = 3,943.66
  5. Step 5: Solve for x
    x = 3,943.66/72.28
  6. Step 6: Final answer
    x = 54.56

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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.