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Finding the Fourth Proportional to 485.86, 670.45 and 289.33

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Solution

The fourth proportional to 485.86, 670.45 and 289.33 is: 399.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.86 : 670.45 = 289.33 : x
  2. Step 2: Convert to fraction form
    485.86/670.45 = 289.33/x
  3. Step 3: Cross multiply
    485.86x = 670.45 × 289.33
  4. Step 4: Simplify right side
    485.86x = 193,981.30
  5. Step 5: Solve for x
    x = 193,981.30/485.86
  6. Step 6: Final answer
    x = 399.25

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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.