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Finding the Fourth Proportional to 485.29, 669.61 and 288.77

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Solution

The fourth proportional to 485.29, 669.61 and 288.77 is: 398.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.29 : 669.61 = 288.77 : x
  2. Step 2: Convert to fraction form
    485.29/669.61 = 288.77/x
  3. Step 3: Cross multiply
    485.29x = 669.61 × 288.77
  4. Step 4: Simplify right side
    485.29x = 193,363.28
  5. Step 5: Solve for x
    x = 193,363.28/485.29
  6. Step 6: Final answer
    x = 398.45

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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.