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Finding the Fourth Proportional to 485.73, 670.74 and 309

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Solution

The fourth proportional to 485.73, 670.74 and 309 is: 426.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.73 : 670.74 = 309 : x
  2. Step 2: Convert to fraction form
    485.73/670.74 = 309/x
  3. Step 3: Cross multiply
    485.73x = 670.74 × 309
  4. Step 4: Simplify right side
    485.73x = 207,258.66
  5. Step 5: Solve for x
    x = 207,258.66/485.73
  6. Step 6: Final answer
    x = 426.70

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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.