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Finding the Fourth Proportional to 157.98, 217.40 and 137.20

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Solution

The fourth proportional to 157.98, 217.40 and 137.20 is: 188.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.98 : 217.40 = 137.20 : x
  2. Step 2: Convert to fraction form
    157.98/217.40 = 137.20/x
  3. Step 3: Cross multiply
    157.98x = 217.40 × 137.20
  4. Step 4: Simplify right side
    157.98x = 29,827.28
  5. Step 5: Solve for x
    x = 29,827.28/157.98
  6. Step 6: Final answer
    x = 188.80

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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.