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Finding the Fourth Proportional to 49, 67.50 and 39.80

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Solution

The fourth proportional to 49, 67.50 and 39.80 is: 54.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    49 : 67.50 = 39.80 : x
  2. Step 2: Convert to fraction form
    49/67.50 = 39.80/x
  3. Step 3: Cross multiply
    49x = 67.50 × 39.80
  4. Step 4: Simplify right side
    49x = 2,686.50
  5. Step 5: Solve for x
    x = 2,686.50/49
  6. Step 6: Final answer
    x = 54.83

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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.