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Finding the Fourth Proportional to 806.34, 1,209.50 and 319.12

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Solution

The fourth proportional to 806.34, 1,209.50 and 319.12 is: 478.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.34 : 1,209.50 = 319.12 : x
  2. Step 2: Convert to fraction form
    806.34/1,209.50 = 319.12/x
  3. Step 3: Cross multiply
    806.34x = 1,209.50 × 319.12
  4. Step 4: Simplify right side
    806.34x = 385,975.64
  5. Step 5: Solve for x
    x = 385,975.64/806.34
  6. Step 6: Final answer
    x = 478.68

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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.