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Finding the Fourth Proportional to 30.85, 42.56 and 19.19

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Solution

The fourth proportional to 30.85, 42.56 and 19.19 is: 26.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.85 : 42.56 = 19.19 : x
  2. Step 2: Convert to fraction form
    30.85/42.56 = 19.19/x
  3. Step 3: Cross multiply
    30.85x = 42.56 × 19.19
  4. Step 4: Simplify right side
    30.85x = 816.73
  5. Step 5: Solve for x
    x = 816.73/30.85
  6. Step 6: Final answer
    x = 26.47

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Find fourth proportional to 15.43, 21.28 and 9.60
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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.