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Finding the Fourth Proportional to 805.84, 1,208.72 and 319.20

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Solution

The fourth proportional to 805.84, 1,208.72 and 319.20 is: 478.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.84 : 1,208.72 = 319.20 : x
  2. Step 2: Convert to fraction form
    805.84/1,208.72 = 319.20/x
  3. Step 3: Cross multiply
    805.84x = 1,208.72 × 319.20
  4. Step 4: Simplify right side
    805.84x = 385,823.42
  5. Step 5: Solve for x
    x = 385,823.42/805.84
  6. Step 6: Final answer
    x = 478.78

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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.