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Finding the Fourth Proportional to 862.08, 1,290.96 and 689.28

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Solution

The fourth proportional to 862.08, 1,290.96 and 689.28 is: 1,032.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.08 : 1,290.96 = 689.28 : x
  2. Step 2: Convert to fraction form
    862.08/1,290.96 = 689.28/x
  3. Step 3: Cross multiply
    862.08x = 1,290.96 × 689.28
  4. Step 4: Simplify right side
    862.08x = 889,832.91
  5. Step 5: Solve for x
    x = 889,832.91/862.08
  6. Step 6: Final answer
    x = 1,032.19

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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.