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Finding the Fourth Proportional to 485.96, 670.62 and 311.40

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Solution

The fourth proportional to 485.96, 670.62 and 311.40 is: 429.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.96 : 670.62 = 311.40 : x
  2. Step 2: Convert to fraction form
    485.96/670.62 = 311.40/x
  3. Step 3: Cross multiply
    485.96x = 670.62 × 311.40
  4. Step 4: Simplify right side
    485.96x = 208,831.07
  5. Step 5: Solve for x
    x = 208,831.07/485.96
  6. Step 6: Final answer
    x = 429.73

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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.