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Finding the Fourth Proportional to 818.20, 1,129.80 and 621.46

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Solution

The fourth proportional to 818.20, 1,129.80 and 621.46 is: 858.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.20 : 1,129.80 = 621.46 : x
  2. Step 2: Convert to fraction form
    818.20/1,129.80 = 621.46/x
  3. Step 3: Cross multiply
    818.20x = 1,129.80 × 621.46
  4. Step 4: Simplify right side
    818.20x = 702,125.51
  5. Step 5: Solve for x
    x = 702,125.51/818.20
  6. Step 6: Final answer
    x = 858.13

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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.