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Finding the Fourth Proportional to 101.21, 139.66 and 57.54

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Solution

The fourth proportional to 101.21, 139.66 and 57.54 is: 79.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.21 : 139.66 = 57.54 : x
  2. Step 2: Convert to fraction form
    101.21/139.66 = 57.54/x
  3. Step 3: Cross multiply
    101.21x = 139.66 × 57.54
  4. Step 4: Simplify right side
    101.21x = 8,035.89
  5. Step 5: Solve for x
    x = 8,035.89/101.21
  6. Step 6: Final answer
    x = 79.40

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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.