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Finding the Fourth Proportional to 157.84, 217.92 and 128.80

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Solution

The fourth proportional to 157.84, 217.92 and 128.80 is: 177.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.84 : 217.92 = 128.80 : x
  2. Step 2: Convert to fraction form
    157.84/217.92 = 128.80/x
  3. Step 3: Cross multiply
    157.84x = 217.92 × 128.80
  4. Step 4: Simplify right side
    157.84x = 28,068.10
  5. Step 5: Solve for x
    x = 28,068.10/157.84
  6. Step 6: Final answer
    x = 177.83

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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.