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Finding the Fourth Proportional to 76.68, 105.84 and 57.36

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Solution

The fourth proportional to 76.68, 105.84 and 57.36 is: 79.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.68 : 105.84 = 57.36 : x
  2. Step 2: Convert to fraction form
    76.68/105.84 = 57.36/x
  3. Step 3: Cross multiply
    76.68x = 105.84 × 57.36
  4. Step 4: Simplify right side
    76.68x = 6,070.98
  5. Step 5: Solve for x
    x = 6,070.98/76.68
  6. Step 6: Final answer
    x = 79.17

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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.