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Finding the Fourth Proportional to 216.98, 299.37 and 128.40

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Solution

The fourth proportional to 216.98, 299.37 and 128.40 is: 177.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.98 : 299.37 = 128.40 : x
  2. Step 2: Convert to fraction form
    216.98/299.37 = 128.40/x
  3. Step 3: Cross multiply
    216.98x = 299.37 × 128.40
  4. Step 4: Simplify right side
    216.98x = 38,439.11
  5. Step 5: Solve for x
    x = 38,439.11/216.98
  6. Step 6: Final answer
    x = 177.16

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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.