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Finding the Fourth Proportional to 823.43, 1,135.30 and 645.84

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Solution

The fourth proportional to 823.43, 1,135.30 and 645.84 is: 890.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    823.43 : 1,135.30 = 645.84 : x
  2. Step 2: Convert to fraction form
    823.43/1,135.30 = 645.84/x
  3. Step 3: Cross multiply
    823.43x = 1,135.30 × 645.84
  4. Step 4: Simplify right side
    823.43x = 733,222.15
  5. Step 5: Solve for x
    x = 733,222.15/823.43
  6. Step 6: Final answer
    x = 890.45

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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.