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Finding the Fourth Proportional to 821.79, 1,134.09 and 490.28

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Solution

The fourth proportional to 821.79, 1,134.09 and 490.28 is: 676.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.79 : 1,134.09 = 490.28 : x
  2. Step 2: Convert to fraction form
    821.79/1,134.09 = 490.28/x
  3. Step 3: Cross multiply
    821.79x = 1,134.09 × 490.28
  4. Step 4: Simplify right side
    821.79x = 556,021.65
  5. Step 5: Solve for x
    x = 556,021.65/821.79
  6. Step 6: Final answer
    x = 676.60

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1.5x scale

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.