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Finding the Fourth Proportional to 102.56, 153.49 and 85.47

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Solution

The fourth proportional to 102.56, 153.49 and 85.47 is: 127.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.56 : 153.49 = 85.47 : x
  2. Step 2: Convert to fraction form
    102.56/153.49 = 85.47/x
  3. Step 3: Cross multiply
    102.56x = 153.49 × 85.47
  4. Step 4: Simplify right side
    102.56x = 13,117.60
  5. Step 5: Solve for x
    x = 13,117.60/102.56
  6. Step 6: Final answer
    x = 127.91

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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.