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Finding the Fourth Proportional to 70.81, 106.15 and 40.39

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Solution

The fourth proportional to 70.81, 106.15 and 40.39 is: 60.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.81 : 106.15 = 40.39 : x
  2. Step 2: Convert to fraction form
    70.81/106.15 = 40.39/x
  3. Step 3: Cross multiply
    70.81x = 106.15 × 40.39
  4. Step 4: Simplify right side
    70.81x = 4,287.40
  5. Step 5: Solve for x
    x = 4,287.40/70.81
  6. Step 6: Final answer
    x = 60.55

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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.