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Finding the Fourth Proportional to 320.80, 439.87 and 289.59

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Solution

The fourth proportional to 320.80, 439.87 and 289.59 is: 397.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.80 : 439.87 = 289.59 : x
  2. Step 2: Convert to fraction form
    320.80/439.87 = 289.59/x
  3. Step 3: Cross multiply
    320.80x = 439.87 × 289.59
  4. Step 4: Simplify right side
    320.80x = 127,381.95
  5. Step 5: Solve for x
    x = 127,381.95/320.80
  6. Step 6: Final answer
    x = 397.08

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.