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Finding the Fourth Proportional to 15.07, 20.78 and 9.61

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Solution

The fourth proportional to 15.07, 20.78 and 9.61 is: 13.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.07 : 20.78 = 9.61 : x
  2. Step 2: Convert to fraction form
    15.07/20.78 = 9.61/x
  3. Step 3: Cross multiply
    15.07x = 20.78 × 9.61
  4. Step 4: Simplify right side
    15.07x = 199.60
  5. Step 5: Solve for x
    x = 199.60/15.07
  6. Step 6: Final answer
    x = 13.25

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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.