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Finding the Fourth Proportional to 485.72, 670.59 and 320.21

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Solution

The fourth proportional to 485.72, 670.59 and 320.21 is: 442.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.72 : 670.59 = 320.21 : x
  2. Step 2: Convert to fraction form
    485.72/670.59 = 320.21/x
  3. Step 3: Cross multiply
    485.72x = 670.59 × 320.21
  4. Step 4: Simplify right side
    485.72x = 214,726.27
  5. Step 5: Solve for x
    x = 214,726.27/485.72
  6. Step 6: Final answer
    x = 442.08

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.