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Finding the Fourth Proportional to 487.55, 672.30 and 321.55

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Solution

The fourth proportional to 487.55, 672.30 and 321.55 is: 443.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.55 : 672.30 = 321.55 : x
  2. Step 2: Convert to fraction form
    487.55/672.30 = 321.55/x
  3. Step 3: Cross multiply
    487.55x = 672.30 × 321.55
  4. Step 4: Simplify right side
    487.55x = 216,177.19
  5. Step 5: Solve for x
    x = 216,177.19/487.55
  6. Step 6: Final answer
    x = 443.40

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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.