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Finding the Fourth Proportional to 78.21, 108.07 and 73.76

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Solution

The fourth proportional to 78.21, 108.07 and 73.76 is: 101.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.21 : 108.07 = 73.76 : x
  2. Step 2: Convert to fraction form
    78.21/108.07 = 73.76/x
  3. Step 3: Cross multiply
    78.21x = 108.07 × 73.76
  4. Step 4: Simplify right side
    78.21x = 7,970.52
  5. Step 5: Solve for x
    x = 7,970.52/78.21
  6. Step 6: Final answer
    x = 101.91

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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.