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Finding the Fourth Proportional to 157.75, 217.80 and 121.10

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Solution

The fourth proportional to 157.75, 217.80 and 121.10 is: 167.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.75 : 217.80 = 121.10 : x
  2. Step 2: Convert to fraction form
    157.75/217.80 = 121.10/x
  3. Step 3: Cross multiply
    157.75x = 217.80 × 121.10
  4. Step 4: Simplify right side
    157.75x = 26,375.58
  5. Step 5: Solve for x
    x = 26,375.58/157.75
  6. Step 6: Final answer
    x = 167.20

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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.