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Finding the Fourth Proportional to 88.34, 121.91 and 81.45

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Solution

The fourth proportional to 88.34, 121.91 and 81.45 is: 112.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.34 : 121.91 = 81.45 : x
  2. Step 2: Convert to fraction form
    88.34/121.91 = 81.45/x
  3. Step 3: Cross multiply
    88.34x = 121.91 × 81.45
  4. Step 4: Simplify right side
    88.34x = 9,929.16
  5. Step 5: Solve for x
    x = 9,929.16/88.34
  6. Step 6: Final answer
    x = 112.40

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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.