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Finding the Fourth Proportional to 259.08, 389.40 and 213.72

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Solution

The fourth proportional to 259.08, 389.40 and 213.72 is: 321.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.08 : 389.40 = 213.72 : x
  2. Step 2: Convert to fraction form
    259.08/389.40 = 213.72/x
  3. Step 3: Cross multiply
    259.08x = 389.40 × 213.72
  4. Step 4: Simplify right side
    259.08x = 83,222.57
  5. Step 5: Solve for x
    x = 83,222.57/259.08
  6. Step 6: Final answer
    x = 321.22

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.