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Finding the Fourth Proportional to 78.74, 108.50 and 75.45

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Solution

The fourth proportional to 78.74, 108.50 and 75.45 is: 103.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.74 : 108.50 = 75.45 : x
  2. Step 2: Convert to fraction form
    78.74/108.50 = 75.45/x
  3. Step 3: Cross multiply
    78.74x = 108.50 × 75.45
  4. Step 4: Simplify right side
    78.74x = 8,185.95
  5. Step 5: Solve for x
    x = 8,185.95/78.74
  6. Step 6: Final answer
    x = 103.97

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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.