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Finding the Fourth Proportional to 85.26, 128.13 and 49.20

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Solution

The fourth proportional to 85.26, 128.13 and 49.20 is: 73.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.26 : 128.13 = 49.20 : x
  2. Step 2: Convert to fraction form
    85.26/128.13 = 49.20/x
  3. Step 3: Cross multiply
    85.26x = 128.13 × 49.20
  4. Step 4: Simplify right side
    85.26x = 6,304.00
  5. Step 5: Solve for x
    x = 6,304.00/85.26
  6. Step 6: Final answer
    x = 73.94

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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.