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Finding the Fourth Proportional to 821.50, 1,133.40 and 490

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Solution

The fourth proportional to 821.50, 1,133.40 and 490 is: 676.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.50 : 1,133.40 = 490 : x
  2. Step 2: Convert to fraction form
    821.50/1,133.40 = 490/x
  3. Step 3: Cross multiply
    821.50x = 1,133.40 × 490
  4. Step 4: Simplify right side
    821.50x = 555,366
  5. Step 5: Solve for x
    x = 555,366/821.50
  6. Step 6: Final answer
    x = 676.04

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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.