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Finding the Fourth Proportional to 680.76, 1,020.38 and 290.66

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Solution

The fourth proportional to 680.76, 1,020.38 and 290.66 is: 435.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.76 : 1,020.38 = 290.66 : x
  2. Step 2: Convert to fraction form
    680.76/1,020.38 = 290.66/x
  3. Step 3: Cross multiply
    680.76x = 1,020.38 × 290.66
  4. Step 4: Simplify right side
    680.76x = 296,577.10
  5. Step 5: Solve for x
    x = 296,577.10/680.76
  6. Step 6: Final answer
    x = 435.66

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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.