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Finding the Fourth Proportional to 15.90, 21.94 and 9.00

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Solution

The fourth proportional to 15.90, 21.94 and 9.00 is: 12.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.90 : 21.94 = 9.00 : x
  2. Step 2: Convert to fraction form
    15.90/21.94 = 9.00/x
  3. Step 3: Cross multiply
    15.90x = 21.94 × 9.00
  4. Step 4: Simplify right side
    15.90x = 197.39
  5. Step 5: Solve for x
    x = 197.39/15.90
  6. Step 6: Final answer
    x = 12.41

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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.