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Finding the Fourth Proportional to 78.43, 108.19 and 48.91

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Solution

The fourth proportional to 78.43, 108.19 and 48.91 is: 67.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.43 : 108.19 = 48.91 : x
  2. Step 2: Convert to fraction form
    78.43/108.19 = 48.91/x
  3. Step 3: Cross multiply
    78.43x = 108.19 × 48.91
  4. Step 4: Simplify right side
    78.43x = 5,291.57
  5. Step 5: Solve for x
    x = 5,291.57/78.43
  6. Step 6: Final answer
    x = 67.47

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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.