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Finding the Fourth Proportional to 85.34, 127.02 and 81.40

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Solution

The fourth proportional to 85.34, 127.02 and 81.40 is: 121.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.34 : 127.02 = 81.40 : x
  2. Step 2: Convert to fraction form
    85.34/127.02 = 81.40/x
  3. Step 3: Cross multiply
    85.34x = 127.02 × 81.40
  4. Step 4: Simplify right side
    85.34x = 10,339.43
  5. Step 5: Solve for x
    x = 10,339.43/85.34
  6. Step 6: Final answer
    x = 121.16

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.