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Finding the Fourth Proportional to 3.19, 4.78 and 0.81

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Solution

The fourth proportional to 3.19, 4.78 and 0.81 is: 1.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.19 : 4.78 = 0.81 : x
  2. Step 2: Convert to fraction form
    3.19/4.78 = 0.81/x
  3. Step 3: Cross multiply
    3.19x = 4.78 × 0.81
  4. Step 4: Simplify right side
    3.19x = 3.88
  5. Step 5: Solve for x
    x = 3.88/3.19
  6. Step 6: Final answer
    x = 1.22

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.