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Finding the Fourth Proportional to 78.52, 107.45 and 76.84

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Solution

The fourth proportional to 78.52, 107.45 and 76.84 is: 105.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.52 : 107.45 = 76.84 : x
  2. Step 2: Convert to fraction form
    78.52/107.45 = 76.84/x
  3. Step 3: Cross multiply
    78.52x = 107.45 × 76.84
  4. Step 4: Simplify right side
    78.52x = 8,256.46
  5. Step 5: Solve for x
    x = 8,256.46/78.52
  6. Step 6: Final answer
    x = 105.15

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.