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Finding the Fourth Proportional to 216.11, 298.10 and 128.76

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Solution

The fourth proportional to 216.11, 298.10 and 128.76 is: 177.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.11 : 298.10 = 128.76 : x
  2. Step 2: Convert to fraction form
    216.11/298.10 = 128.76/x
  3. Step 3: Cross multiply
    216.11x = 298.10 × 128.76
  4. Step 4: Simplify right side
    216.11x = 38,382.71
  5. Step 5: Solve for x
    x = 38,382.71/216.11
  6. Step 6: Final answer
    x = 177.61

Related Problems

Find fourth proportional to 108.05, 149.05 and 64.38
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Double scale
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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.