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Finding the Fourth Proportional to 806.70, 1,209 and 319.08

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Solution

The fourth proportional to 806.70, 1,209 and 319.08 is: 478.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.70 : 1,209 = 319.08 : x
  2. Step 2: Convert to fraction form
    806.70/1,209 = 319.08/x
  3. Step 3: Cross multiply
    806.70x = 1,209 × 319.08
  4. Step 4: Simplify right side
    806.70x = 385,767.72
  5. Step 5: Solve for x
    x = 385,767.72/806.70
  6. Step 6: Final answer
    x = 478.20

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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.