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Finding the Fourth Proportional to 216.79, 299.18 and 128.33

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Solution

The fourth proportional to 216.79, 299.18 and 128.33 is: 177.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.79 : 299.18 = 128.33 : x
  2. Step 2: Convert to fraction form
    216.79/299.18 = 128.33/x
  3. Step 3: Cross multiply
    216.79x = 299.18 × 128.33
  4. Step 4: Simplify right side
    216.79x = 38,393.88
  5. Step 5: Solve for x
    x = 38,393.88/216.79
  6. Step 6: Final answer
    x = 177.10

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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.