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Finding the Fourth Proportional to 809.21, 1,214.10 and 398.30

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Solution

The fourth proportional to 809.21, 1,214.10 and 398.30 is: 597.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.21 : 1,214.10 = 398.30 : x
  2. Step 2: Convert to fraction form
    809.21/1,214.10 = 398.30/x
  3. Step 3: Cross multiply
    809.21x = 1,214.10 × 398.30
  4. Step 4: Simplify right side
    809.21x = 483,576.03
  5. Step 5: Solve for x
    x = 483,576.03/809.21
  6. Step 6: Final answer
    x = 597.59

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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.