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Finding the Fourth Proportional to 109.66, 151.19 and 78.55

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Solution

The fourth proportional to 109.66, 151.19 and 78.55 is: 108.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.66 : 151.19 = 78.55 : x
  2. Step 2: Convert to fraction form
    109.66/151.19 = 78.55/x
  3. Step 3: Cross multiply
    109.66x = 151.19 × 78.55
  4. Step 4: Simplify right side
    109.66x = 11,875.97
  5. Step 5: Solve for x
    x = 11,875.97/109.66
  6. Step 6: Final answer
    x = 108.30

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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.