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Finding the Fourth Proportional to 109.89, 152.70 and 108.78

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Solution

The fourth proportional to 109.89, 152.70 and 108.78 is: 151.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.89 : 152.70 = 108.78 : x
  2. Step 2: Convert to fraction form
    109.89/152.70 = 108.78/x
  3. Step 3: Cross multiply
    109.89x = 152.70 × 108.78
  4. Step 4: Simplify right side
    109.89x = 16,610.71
  5. Step 5: Solve for x
    x = 16,610.71/109.89
  6. Step 6: Final answer
    x = 151.16

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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.