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Finding the Fourth Proportional to 154.10, 212.56 and 121.30

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Solution

The fourth proportional to 154.10, 212.56 and 121.30 is: 167.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.10 : 212.56 = 121.30 : x
  2. Step 2: Convert to fraction form
    154.10/212.56 = 121.30/x
  3. Step 3: Cross multiply
    154.10x = 212.56 × 121.30
  4. Step 4: Simplify right side
    154.10x = 25,782.69
  5. Step 5: Solve for x
    x = 25,782.69/154.10
  6. Step 6: Final answer
    x = 167.31

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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.