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Finding the Fourth Proportional to 85.73, 128.00 and 70.55

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Solution

The fourth proportional to 85.73, 128.00 and 70.55 is: 105.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.73 : 128.00 = 70.55 : x
  2. Step 2: Convert to fraction form
    85.73/128.00 = 70.55/x
  3. Step 3: Cross multiply
    85.73x = 128.00 × 70.55
  4. Step 4: Simplify right side
    85.73x = 9,029.41
  5. Step 5: Solve for x
    x = 9,029.41/85.73
  6. Step 6: Final answer
    x = 105.32

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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.