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Finding the Fourth Proportional to 84.15, 126.18 and 38.45

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Solution

The fourth proportional to 84.15, 126.18 and 38.45 is: 57.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.15 : 126.18 = 38.45 : x
  2. Step 2: Convert to fraction form
    84.15/126.18 = 38.45/x
  3. Step 3: Cross multiply
    84.15x = 126.18 × 38.45
  4. Step 4: Simplify right side
    84.15x = 4,851.23
  5. Step 5: Solve for x
    x = 4,851.23/84.15
  6. Step 6: Final answer
    x = 57.65

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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.