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Finding the Fourth Proportional to 49.90, 68.78 and 40.18

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Solution

The fourth proportional to 49.90, 68.78 and 40.18 is: 55.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    49.90 : 68.78 = 40.18 : x
  2. Step 2: Convert to fraction form
    49.90/68.78 = 40.18/x
  3. Step 3: Cross multiply
    49.90x = 68.78 × 40.18
  4. Step 4: Simplify right side
    49.90x = 2,763.58
  5. Step 5: Solve for x
    x = 2,763.58/49.90
  6. Step 6: Final answer
    x = 55.38

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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.