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Finding the Fourth Proportional to 78.38, 108.15 and 48.86

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Solution

The fourth proportional to 78.38, 108.15 and 48.86 is: 67.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.38 : 108.15 = 48.86 : x
  2. Step 2: Convert to fraction form
    78.38/108.15 = 48.86/x
  3. Step 3: Cross multiply
    78.38x = 108.15 × 48.86
  4. Step 4: Simplify right side
    78.38x = 5,283.67
  5. Step 5: Solve for x
    x = 5,283.67/78.38
  6. Step 6: Final answer
    x = 67.42

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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.