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Finding the Fourth Proportional to 108.50, 149.74 and 69.78

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Solution

The fourth proportional to 108.50, 149.74 and 69.78 is: 96.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.50 : 149.74 = 69.78 : x
  2. Step 2: Convert to fraction form
    108.50/149.74 = 69.78/x
  3. Step 3: Cross multiply
    108.50x = 149.74 × 69.78
  4. Step 4: Simplify right side
    108.50x = 10,448.86
  5. Step 5: Solve for x
    x = 10,448.86/108.50
  6. Step 6: Final answer
    x = 96.30

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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.