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Finding the Fourth Proportional to 19.19, 28.77 and 7.78

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Solution

The fourth proportional to 19.19, 28.77 and 7.78 is: 11.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.19 : 28.77 = 7.78 : x
  2. Step 2: Convert to fraction form
    19.19/28.77 = 7.78/x
  3. Step 3: Cross multiply
    19.19x = 28.77 × 7.78
  4. Step 4: Simplify right side
    19.19x = 223.69
  5. Step 5: Solve for x
    x = 223.69/19.19
  6. Step 6: Final answer
    x = 11.66

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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.