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Finding the Fourth Proportional to 678.29, 1,020.83 and 611.19

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Solution

The fourth proportional to 678.29, 1,020.83 and 611.19 is: 919.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.29 : 1,020.83 = 611.19 : x
  2. Step 2: Convert to fraction form
    678.29/1,020.83 = 611.19/x
  3. Step 3: Cross multiply
    678.29x = 1,020.83 × 611.19
  4. Step 4: Simplify right side
    678.29x = 623,918.03
  5. Step 5: Solve for x
    x = 623,918.03/678.29
  6. Step 6: Final answer
    x = 919.85

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.