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Finding the Fourth Proportional to 806.85, 1,210.34 and 390.26

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Solution

The fourth proportional to 806.85, 1,210.34 and 390.26 is: 585.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.85 : 1,210.34 = 390.26 : x
  2. Step 2: Convert to fraction form
    806.85/1,210.34 = 390.26/x
  3. Step 3: Cross multiply
    806.85x = 1,210.34 × 390.26
  4. Step 4: Simplify right side
    806.85x = 472,339.29
  5. Step 5: Solve for x
    x = 472,339.29/806.85
  6. Step 6: Final answer
    x = 585.41

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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.