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Finding the Fourth Proportional to 46.40, 63.88 and 39.80

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Solution

The fourth proportional to 46.40, 63.88 and 39.80 is: 54.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    46.40 : 63.88 = 39.80 : x
  2. Step 2: Convert to fraction form
    46.40/63.88 = 39.80/x
  3. Step 3: Cross multiply
    46.40x = 63.88 × 39.80
  4. Step 4: Simplify right side
    46.40x = 2,542.42
  5. Step 5: Solve for x
    x = 2,542.42/46.40
  6. Step 6: Final answer
    x = 54.79

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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.