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Finding the Fourth Proportional to 821.63, 1,233.05 and 388.79

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Solution

The fourth proportional to 821.63, 1,233.05 and 388.79 is: 583.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.63 : 1,233.05 = 388.79 : x
  2. Step 2: Convert to fraction form
    821.63/1,233.05 = 388.79/x
  3. Step 3: Cross multiply
    821.63x = 1,233.05 × 388.79
  4. Step 4: Simplify right side
    821.63x = 479,389.40
  5. Step 5: Solve for x
    x = 479,389.40/821.63
  6. Step 6: Final answer
    x = 583.46

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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.