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Finding the Fourth Proportional to 88.56, 121.91 and 65.21

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Solution

The fourth proportional to 88.56, 121.91 and 65.21 is: 89.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.56 : 121.91 = 65.21 : x
  2. Step 2: Convert to fraction form
    88.56/121.91 = 65.21/x
  3. Step 3: Cross multiply
    88.56x = 121.91 × 65.21
  4. Step 4: Simplify right side
    88.56x = 7,948.82
  5. Step 5: Solve for x
    x = 7,948.82/88.56
  6. Step 6: Final answer
    x = 89.76

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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.