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Finding the Fourth Proportional to 109.01, 163.40 and 78.71

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Solution

The fourth proportional to 109.01, 163.40 and 78.71 is: 117.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.01 : 163.40 = 78.71 : x
  2. Step 2: Convert to fraction form
    109.01/163.40 = 78.71/x
  3. Step 3: Cross multiply
    109.01x = 163.40 × 78.71
  4. Step 4: Simplify right side
    109.01x = 12,860.82
  5. Step 5: Solve for x
    x = 12,860.82/109.01
  6. Step 6: Final answer
    x = 117.98

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.