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Finding the Fourth Proportional to 806.70, 1,210.67 and 319.79

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Solution

The fourth proportional to 806.70, 1,210.67 and 319.79 is: 479.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.70 : 1,210.67 = 319.79 : x
  2. Step 2: Convert to fraction form
    806.70/1,210.67 = 319.79/x
  3. Step 3: Cross multiply
    806.70x = 1,210.67 × 319.79
  4. Step 4: Simplify right side
    806.70x = 387,162.79
  5. Step 5: Solve for x
    x = 387,162.79/806.70
  6. Step 6: Final answer
    x = 479.93

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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.