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Finding the Fourth Proportional to 680.81, 1,020.80 and 372.40

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Solution

The fourth proportional to 680.81, 1,020.80 and 372.40 is: 558.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.81 : 1,020.80 = 372.40 : x
  2. Step 2: Convert to fraction form
    680.81/1,020.80 = 372.40/x
  3. Step 3: Cross multiply
    680.81x = 1,020.80 × 372.40
  4. Step 4: Simplify right side
    680.81x = 380,144.30
  5. Step 5: Solve for x
    x = 380,144.30/680.81
  6. Step 6: Final answer
    x = 558.37

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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.