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Finding the Fourth Proportional to 10.42, 15.61 and 8.15

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Solution

The fourth proportional to 10.42, 15.61 and 8.15 is: 12.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.42 : 15.61 = 8.15 : x
  2. Step 2: Convert to fraction form
    10.42/15.61 = 8.15/x
  3. Step 3: Cross multiply
    10.42x = 15.61 × 8.15
  4. Step 4: Simplify right side
    10.42x = 127.22
  5. Step 5: Solve for x
    x = 127.22/10.42
  6. Step 6: Final answer
    x = 12.21

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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.