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Finding the Fourth Proportional to 822.40, 1,230.90 and 579.40

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Solution

The fourth proportional to 822.40, 1,230.90 and 579.40 is: 867.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    822.40 : 1,230.90 = 579.40 : x
  2. Step 2: Convert to fraction form
    822.40/1,230.90 = 579.40/x
  3. Step 3: Cross multiply
    822.40x = 1,230.90 × 579.40
  4. Step 4: Simplify right side
    822.40x = 713,183.46
  5. Step 5: Solve for x
    x = 713,183.46/822.40
  6. Step 6: Final answer
    x = 867.20

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1.5x scale

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.