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Finding the Fourth Proportional to 85.61, 128.40 and 58.73

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Solution

The fourth proportional to 85.61, 128.40 and 58.73 is: 88.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.61 : 128.40 = 58.73 : x
  2. Step 2: Convert to fraction form
    85.61/128.40 = 58.73/x
  3. Step 3: Cross multiply
    85.61x = 128.40 × 58.73
  4. Step 4: Simplify right side
    85.61x = 7,540.93
  5. Step 5: Solve for x
    x = 7,540.93/85.61
  6. Step 6: Final answer
    x = 88.08

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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.