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Finding the Fourth Proportional to 78.15, 107.77 and 57.49

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Solution

The fourth proportional to 78.15, 107.77 and 57.49 is: 79.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.15 : 107.77 = 57.49 : x
  2. Step 2: Convert to fraction form
    78.15/107.77 = 57.49/x
  3. Step 3: Cross multiply
    78.15x = 107.77 × 57.49
  4. Step 4: Simplify right side
    78.15x = 6,195.70
  5. Step 5: Solve for x
    x = 6,195.70/78.15
  6. Step 6: Final answer
    x = 79.28

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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.