Home / 820.20-1,229.90-542.10

Finding the Fourth Proportional to 820.20, 1,229.90 and 542.10

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Solution

The fourth proportional to 820.20, 1,229.90 and 542.10 is: 812.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.20 : 1,229.90 = 542.10 : x
  2. Step 2: Convert to fraction form
    820.20/1,229.90 = 542.10/x
  3. Step 3: Cross multiply
    820.20x = 1,229.90 × 542.10
  4. Step 4: Simplify right side
    820.20x = 666,726.08
  5. Step 5: Solve for x
    x = 666,726.08/820.20
  6. Step 6: Final answer
    x = 812.88

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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.