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Finding the Fourth Proportional to 485.78, 670.32 and 354.56

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Solution

The fourth proportional to 485.78, 670.32 and 354.56 is: 489.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.78 : 670.32 = 354.56 : x
  2. Step 2: Convert to fraction form
    485.78/670.32 = 354.56/x
  3. Step 3: Cross multiply
    485.78x = 670.32 × 354.56
  4. Step 4: Simplify right side
    485.78x = 237,670.34
  5. Step 5: Solve for x
    x = 237,670.34/485.78
  6. Step 6: Final answer
    x = 489.25

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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.