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Finding the Fourth Proportional to 85.67, 128.42 and 49.07

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Solution

The fourth proportional to 85.67, 128.42 and 49.07 is: 73.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.67 : 128.42 = 49.07 : x
  2. Step 2: Convert to fraction form
    85.67/128.42 = 49.07/x
  3. Step 3: Cross multiply
    85.67x = 128.42 × 49.07
  4. Step 4: Simplify right side
    85.67x = 6,300.68
  5. Step 5: Solve for x
    x = 6,300.68/85.67
  6. Step 6: Final answer
    x = 73.55

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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.