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Finding the Fourth Proportional to 320.85, 480.65 and 287.99

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Solution

The fourth proportional to 320.85, 480.65 and 287.99 is: 431.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.85 : 480.65 = 287.99 : x
  2. Step 2: Convert to fraction form
    320.85/480.65 = 287.99/x
  3. Step 3: Cross multiply
    320.85x = 480.65 × 287.99
  4. Step 4: Simplify right side
    320.85x = 138,422.39
  5. Step 5: Solve for x
    x = 138,422.39/320.85
  6. Step 6: Final answer
    x = 431.42

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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.