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Finding the Fourth Proportional to 216.16, 298.29 and 128.86

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Solution

The fourth proportional to 216.16, 298.29 and 128.86 is: 177.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.16 : 298.29 = 128.86 : x
  2. Step 2: Convert to fraction form
    216.16/298.29 = 128.86/x
  3. Step 3: Cross multiply
    216.16x = 298.29 × 128.86
  4. Step 4: Simplify right side
    216.16x = 38,437.65
  5. Step 5: Solve for x
    x = 38,437.65/216.16
  6. Step 6: Final answer
    x = 177.82

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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.