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Finding the Fourth Proportional to 806.74, 1,209.50 and 319.66

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Solution

The fourth proportional to 806.74, 1,209.50 and 319.66 is: 479.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.74 : 1,209.50 = 319.66 : x
  2. Step 2: Convert to fraction form
    806.74/1,209.50 = 319.66/x
  3. Step 3: Cross multiply
    806.74x = 1,209.50 × 319.66
  4. Step 4: Simplify right side
    806.74x = 386,621.12
  5. Step 5: Solve for x
    x = 386,621.12/806.74
  6. Step 6: Final answer
    x = 479.24

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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.