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Finding the Fourth Proportional to 112.39, 154.91 and 87.78

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Solution

The fourth proportional to 112.39, 154.91 and 87.78 is: 121.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.39 : 154.91 = 87.78 : x
  2. Step 2: Convert to fraction form
    112.39/154.91 = 87.78/x
  3. Step 3: Cross multiply
    112.39x = 154.91 × 87.78
  4. Step 4: Simplify right side
    112.39x = 13,598.80
  5. Step 5: Solve for x
    x = 13,598.80/112.39
  6. Step 6: Final answer
    x = 121.00

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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.