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Finding the Fourth Proportional to 217.02, 299.50 and 128.56

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Solution

The fourth proportional to 217.02, 299.50 and 128.56 is: 177.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.02 : 299.50 = 128.56 : x
  2. Step 2: Convert to fraction form
    217.02/299.50 = 128.56/x
  3. Step 3: Cross multiply
    217.02x = 299.50 × 128.56
  4. Step 4: Simplify right side
    217.02x = 38,503.72
  5. Step 5: Solve for x
    x = 38,503.72/217.02
  6. Step 6: Final answer
    x = 177.42

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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.