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Finding the Fourth Proportional to 216.19, 298.25 and 128.86

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Solution

The fourth proportional to 216.19, 298.25 and 128.86 is: 177.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.19 : 298.25 = 128.86 : x
  2. Step 2: Convert to fraction form
    216.19/298.25 = 128.86/x
  3. Step 3: Cross multiply
    216.19x = 298.25 × 128.86
  4. Step 4: Simplify right side
    216.19x = 38,431.85
  5. Step 5: Solve for x
    x = 38,431.85/216.19
  6. Step 6: Final answer
    x = 177.77

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1.5x scale

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.