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Finding the Fourth Proportional to 71.54, 98.72 and 38.79

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Solution

The fourth proportional to 71.54, 98.72 and 38.79 is: 53.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.54 : 98.72 = 38.79 : x
  2. Step 2: Convert to fraction form
    71.54/98.72 = 38.79/x
  3. Step 3: Cross multiply
    71.54x = 98.72 × 38.79
  4. Step 4: Simplify right side
    71.54x = 3,829.05
  5. Step 5: Solve for x
    x = 3,829.05/71.54
  6. Step 6: Final answer
    x = 53.53

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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.