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Finding the Fourth Proportional to 78.21, 108.48 and 75.99

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Solution

The fourth proportional to 78.21, 108.48 and 75.99 is: 105.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.21 : 108.48 = 75.99 : x
  2. Step 2: Convert to fraction form
    78.21/108.48 = 75.99/x
  3. Step 3: Cross multiply
    78.21x = 108.48 × 75.99
  4. Step 4: Simplify right side
    78.21x = 8,243.40
  5. Step 5: Solve for x
    x = 8,243.40/78.21
  6. Step 6: Final answer
    x = 105.40

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.