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Finding the Fourth Proportional to 30.21, 45.36 and 19.38

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Solution

The fourth proportional to 30.21, 45.36 and 19.38 is: 29.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.21 : 45.36 = 19.38 : x
  2. Step 2: Convert to fraction form
    30.21/45.36 = 19.38/x
  3. Step 3: Cross multiply
    30.21x = 45.36 × 19.38
  4. Step 4: Simplify right side
    30.21x = 878.98
  5. Step 5: Solve for x
    x = 878.98/30.21
  6. Step 6: Final answer
    x = 29.10

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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.