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Finding the Fourth Proportional to 157.50, 217.08 and 129.78

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Solution

The fourth proportional to 157.50, 217.08 and 129.78 is: 178.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.50 : 217.08 = 129.78 : x
  2. Step 2: Convert to fraction form
    157.50/217.08 = 129.78/x
  3. Step 3: Cross multiply
    157.50x = 217.08 × 129.78
  4. Step 4: Simplify right side
    157.50x = 28,172.64
  5. Step 5: Solve for x
    x = 28,172.64/157.50
  6. Step 6: Final answer
    x = 178.87

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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.