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Finding the Fourth Proportional to 390.21, 584.64 and 355.92

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Solution

The fourth proportional to 390.21, 584.64 and 355.92 is: 533.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.21 : 584.64 = 355.92 : x
  2. Step 2: Convert to fraction form
    390.21/584.64 = 355.92/x
  3. Step 3: Cross multiply
    390.21x = 584.64 × 355.92
  4. Step 4: Simplify right side
    390.21x = 208,085.07
  5. Step 5: Solve for x
    x = 208,085.07/390.21
  6. Step 6: Final answer
    x = 533.26

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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.