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Finding the Fourth Proportional to 390.21, 582.45 and 344.08

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Solution

The fourth proportional to 390.21, 582.45 and 344.08 is: 513.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.21 : 582.45 = 344.08 : x
  2. Step 2: Convert to fraction form
    390.21/582.45 = 344.08/x
  3. Step 3: Cross multiply
    390.21x = 582.45 × 344.08
  4. Step 4: Simplify right side
    390.21x = 200,409.40
  5. Step 5: Solve for x
    x = 200,409.40/390.21
  6. Step 6: Final answer
    x = 513.59

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.