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Finding the Fourth Proportional to 154.87, 213.69 and 89.40

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Solution

The fourth proportional to 154.87, 213.69 and 89.40 is: 123.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.87 : 213.69 = 89.40 : x
  2. Step 2: Convert to fraction form
    154.87/213.69 = 89.40/x
  3. Step 3: Cross multiply
    154.87x = 213.69 × 89.40
  4. Step 4: Simplify right side
    154.87x = 19,102.82
  5. Step 5: Solve for x
    x = 19,102.82/154.87
  6. Step 6: Final answer
    x = 123.35

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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.