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Finding the Fourth Proportional to 78, 106.93 and 76.63

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Solution

The fourth proportional to 78, 106.93 and 76.63 is: 105.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    78 : 106.93 = 76.63 : x
  2. Step 2: Convert to fraction form
    78/106.93 = 76.63/x
  3. Step 3: Cross multiply
    78x = 106.93 × 76.63
  4. Step 4: Simplify right side
    78x = 8,194.05
  5. Step 5: Solve for x
    x = 8,194.05/78
  6. Step 6: Final answer
    x = 105.05

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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.