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Finding the Fourth Proportional to 818.48, 1,229.40 and 657.20

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Solution

The fourth proportional to 818.48, 1,229.40 and 657.20 is: 987.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.48 : 1,229.40 = 657.20 : x
  2. Step 2: Convert to fraction form
    818.48/1,229.40 = 657.20/x
  3. Step 3: Cross multiply
    818.48x = 1,229.40 × 657.20
  4. Step 4: Simplify right side
    818.48x = 807,961.68
  5. Step 5: Solve for x
    x = 807,961.68/818.48
  6. Step 6: Final answer
    x = 987.15

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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.