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Finding the Fourth Proportional to 40.38, 55.66 and 30.70

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Solution

The fourth proportional to 40.38, 55.66 and 30.70 is: 42.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.38 : 55.66 = 30.70 : x
  2. Step 2: Convert to fraction form
    40.38/55.66 = 30.70/x
  3. Step 3: Cross multiply
    40.38x = 55.66 × 30.70
  4. Step 4: Simplify right side
    40.38x = 1,708.76
  5. Step 5: Solve for x
    x = 1,708.76/40.38
  6. Step 6: Final answer
    x = 42.32

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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.