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Finding the Fourth Proportional to 217.07, 299.49 and 128.51

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Solution

The fourth proportional to 217.07, 299.49 and 128.51 is: 177.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.07 : 299.49 = 128.51 : x
  2. Step 2: Convert to fraction form
    217.07/299.49 = 128.51/x
  3. Step 3: Cross multiply
    217.07x = 299.49 × 128.51
  4. Step 4: Simplify right side
    217.07x = 38,485.96
  5. Step 5: Solve for x
    x = 38,485.96/217.07
  6. Step 6: Final answer
    x = 177.30

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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.