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Finding the Fourth Proportional to 88.90, 122.81 and 71.39

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Solution

The fourth proportional to 88.90, 122.81 and 71.39 is: 98.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.90 : 122.81 = 71.39 : x
  2. Step 2: Convert to fraction form
    88.90/122.81 = 71.39/x
  3. Step 3: Cross multiply
    88.90x = 122.81 × 71.39
  4. Step 4: Simplify right side
    88.90x = 8,767.05
  5. Step 5: Solve for x
    x = 8,767.05/88.90
  6. Step 6: Final answer
    x = 98.62

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.