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Finding the Fourth Proportional to 812.12, 1,119.30 and 646.88

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Solution

The fourth proportional to 812.12, 1,119.30 and 646.88 is: 891.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.12 : 1,119.30 = 646.88 : x
  2. Step 2: Convert to fraction form
    812.12/1,119.30 = 646.88/x
  3. Step 3: Cross multiply
    812.12x = 1,119.30 × 646.88
  4. Step 4: Simplify right side
    812.12x = 724,052.78
  5. Step 5: Solve for x
    x = 724,052.78/812.12
  6. Step 6: Final answer
    x = 891.56

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.