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Finding the Fourth Proportional to 983.20, 1,355.80 and 684.79

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Solution

The fourth proportional to 983.20, 1,355.80 and 684.79 is: 944.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    983.20 : 1,355.80 = 684.79 : x
  2. Step 2: Convert to fraction form
    983.20/1,355.80 = 684.79/x
  3. Step 3: Cross multiply
    983.20x = 1,355.80 × 684.79
  4. Step 4: Simplify right side
    983.20x = 928,438.28
  5. Step 5: Solve for x
    x = 928,438.28/983.20
  6. Step 6: Final answer
    x = 944.30

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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.