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Finding the Fourth Proportional to 88.10, 121.61 and 55.40

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Solution

The fourth proportional to 88.10, 121.61 and 55.40 is: 76.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.10 : 121.61 = 55.40 : x
  2. Step 2: Convert to fraction form
    88.10/121.61 = 55.40/x
  3. Step 3: Cross multiply
    88.10x = 121.61 × 55.40
  4. Step 4: Simplify right side
    88.10x = 6,737.19
  5. Step 5: Solve for x
    x = 6,737.19/88.10
  6. Step 6: Final answer
    x = 76.47

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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.