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Finding the Fourth Proportional to 806.90, 1,210.28 and 319.97

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Solution

The fourth proportional to 806.90, 1,210.28 and 319.97 is: 479.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.90 : 1,210.28 = 319.97 : x
  2. Step 2: Convert to fraction form
    806.90/1,210.28 = 319.97/x
  3. Step 3: Cross multiply
    806.90x = 1,210.28 × 319.97
  4. Step 4: Simplify right side
    806.90x = 387,254.72
  5. Step 5: Solve for x
    x = 387,254.72/806.90
  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.