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Finding the Fourth Proportional to 85.43, 127.61 and 77.30

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Solution

The fourth proportional to 85.43, 127.61 and 77.30 is: 115.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.43 : 127.61 = 77.30 : x
  2. Step 2: Convert to fraction form
    85.43/127.61 = 77.30/x
  3. Step 3: Cross multiply
    85.43x = 127.61 × 77.30
  4. Step 4: Simplify right side
    85.43x = 9,863.23
  5. Step 5: Solve for x
    x = 9,863.23/85.43
  6. Step 6: Final answer
    x = 115.45

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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.