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Finding the Fourth Proportional to 52.15, 71.95 and 39.85

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Solution

The fourth proportional to 52.15, 71.95 and 39.85 is: 54.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.15 : 71.95 = 39.85 : x
  2. Step 2: Convert to fraction form
    52.15/71.95 = 39.85/x
  3. Step 3: Cross multiply
    52.15x = 71.95 × 39.85
  4. Step 4: Simplify right side
    52.15x = 2,867.21
  5. Step 5: Solve for x
    x = 2,867.21/52.15
  6. Step 6: Final answer
    x = 54.98

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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.