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Finding the Fourth Proportional to 112.30, 155.07 and 87.70

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Solution

The fourth proportional to 112.30, 155.07 and 87.70 is: 121.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.30 : 155.07 = 87.70 : x
  2. Step 2: Convert to fraction form
    112.30/155.07 = 87.70/x
  3. Step 3: Cross multiply
    112.30x = 155.07 × 87.70
  4. Step 4: Simplify right side
    112.30x = 13,599.64
  5. Step 5: Solve for x
    x = 13,599.64/112.30
  6. Step 6: Final answer
    x = 121.10

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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.