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Finding the Fourth Proportional to 821.48, 1,133.58 and 490

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Solution

The fourth proportional to 821.48, 1,133.58 and 490 is: 676.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.48 : 1,133.58 = 490 : x
  2. Step 2: Convert to fraction form
    821.48/1,133.58 = 490/x
  3. Step 3: Cross multiply
    821.48x = 1,133.58 × 490
  4. Step 4: Simplify right side
    821.48x = 555,454.20
  5. Step 5: Solve for x
    x = 555,454.20/821.48
  6. Step 6: Final answer
    x = 676.16

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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.