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Finding the Fourth Proportional to 818.30, 1,128.84 and 621.47

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Solution

The fourth proportional to 818.30, 1,128.84 and 621.47 is: 857.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.30 : 1,128.84 = 621.47 : x
  2. Step 2: Convert to fraction form
    818.30/1,128.84 = 621.47/x
  3. Step 3: Cross multiply
    818.30x = 1,128.84 × 621.47
  4. Step 4: Simplify right side
    818.30x = 701,540.69
  5. Step 5: Solve for x
    x = 701,540.69/818.30
  6. Step 6: Final answer
    x = 857.31

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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.