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Finding the Fourth Proportional to 77.90, 107.42 and 54.58

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Solution

The fourth proportional to 77.90, 107.42 and 54.58 is: 75.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.90 : 107.42 = 54.58 : x
  2. Step 2: Convert to fraction form
    77.90/107.42 = 54.58/x
  3. Step 3: Cross multiply
    77.90x = 107.42 × 54.58
  4. Step 4: Simplify right side
    77.90x = 5,862.99
  5. Step 5: Solve for x
    x = 5,862.99/77.90
  6. Step 6: Final answer
    x = 75.26

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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.