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Finding the Fourth Proportional to 67.40, 93.01 and 39.78

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Solution

The fourth proportional to 67.40, 93.01 and 39.78 is: 54.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.40 : 93.01 = 39.78 : x
  2. Step 2: Convert to fraction form
    67.40/93.01 = 39.78/x
  3. Step 3: Cross multiply
    67.40x = 93.01 × 39.78
  4. Step 4: Simplify right side
    67.40x = 3,699.94
  5. Step 5: Solve for x
    x = 3,699.94/67.40
  6. Step 6: Final answer
    x = 54.90

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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.