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Finding the Fourth Proportional to 10.47, 15.78 and 8.49

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Solution

The fourth proportional to 10.47, 15.78 and 8.49 is: 12.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.47 : 15.78 = 8.49 : x
  2. Step 2: Convert to fraction form
    10.47/15.78 = 8.49/x
  3. Step 3: Cross multiply
    10.47x = 15.78 × 8.49
  4. Step 4: Simplify right side
    10.47x = 133.97
  5. Step 5: Solve for x
    x = 133.97/10.47
  6. Step 6: Final answer
    x = 12.80

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.