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Finding the Fourth Proportional to 818.65, 1,129.84 and 685.64

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Solution

The fourth proportional to 818.65, 1,129.84 and 685.64 is: 946.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.65 : 1,129.84 = 685.64 : x
  2. Step 2: Convert to fraction form
    818.65/1,129.84 = 685.64/x
  3. Step 3: Cross multiply
    818.65x = 1,129.84 × 685.64
  4. Step 4: Simplify right side
    818.65x = 774,664.61
  5. Step 5: Solve for x
    x = 774,664.61/818.65
  6. Step 6: Final answer
    x = 946.27

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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.