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Finding the Fourth Proportional to 15.83, 21.85 and 10.91

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Solution

The fourth proportional to 15.83, 21.85 and 10.91 is: 15.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.83 : 21.85 = 10.91 : x
  2. Step 2: Convert to fraction form
    15.83/21.85 = 10.91/x
  3. Step 3: Cross multiply
    15.83x = 21.85 × 10.91
  4. Step 4: Simplify right side
    15.83x = 238.45
  5. Step 5: Solve for x
    x = 238.45/15.83
  6. Step 6: Final answer
    x = 15.07

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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.