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Finding the Fourth Proportional to 809.21, 1,214.08 and 398.39

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Solution

The fourth proportional to 809.21, 1,214.08 and 398.39 is: 597.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.21 : 1,214.08 = 398.39 : x
  2. Step 2: Convert to fraction form
    809.21/1,214.08 = 398.39/x
  3. Step 3: Cross multiply
    809.21x = 1,214.08 × 398.39
  4. Step 4: Simplify right side
    809.21x = 483,670.26
  5. Step 5: Solve for x
    x = 483,670.26/809.21
  6. Step 6: Final answer
    x = 597.70

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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.