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Finding the Fourth Proportional to 78.17, 107.87 and 45.42

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Solution

The fourth proportional to 78.17, 107.87 and 45.42 is: 62.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.17 : 107.87 = 45.42 : x
  2. Step 2: Convert to fraction form
    78.17/107.87 = 45.42/x
  3. Step 3: Cross multiply
    78.17x = 107.87 × 45.42
  4. Step 4: Simplify right side
    78.17x = 4,899.46
  5. Step 5: Solve for x
    x = 4,899.46/78.17
  6. Step 6: Final answer
    x = 62.68

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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.