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Finding the Fourth Proportional to 806.22, 1,209.33 and 643.50

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Solution

The fourth proportional to 806.22, 1,209.33 and 643.50 is: 965.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.22 : 1,209.33 = 643.50 : x
  2. Step 2: Convert to fraction form
    806.22/1,209.33 = 643.50/x
  3. Step 3: Cross multiply
    806.22x = 1,209.33 × 643.50
  4. Step 4: Simplify right side
    806.22x = 778,203.86
  5. Step 5: Solve for x
    x = 778,203.86/806.22
  6. Step 6: Final answer
    x = 965.25

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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.