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Finding the Fourth Proportional to 48.80, 72.90 and 40.72

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Solution

The fourth proportional to 48.80, 72.90 and 40.72 is: 60.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    48.80 : 72.90 = 40.72 : x
  2. Step 2: Convert to fraction form
    48.80/72.90 = 40.72/x
  3. Step 3: Cross multiply
    48.80x = 72.90 × 40.72
  4. Step 4: Simplify right side
    48.80x = 2,968.49
  5. Step 5: Solve for x
    x = 2,968.49/48.80
  6. Step 6: Final answer
    x = 60.83

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.