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Finding the Fourth Proportional to 485.65, 728.70 and 254.80

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Solution

The fourth proportional to 485.65, 728.70 and 254.80 is: 382.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.65 : 728.70 = 254.80 : x
  2. Step 2: Convert to fraction form
    485.65/728.70 = 254.80/x
  3. Step 3: Cross multiply
    485.65x = 728.70 × 254.80
  4. Step 4: Simplify right side
    485.65x = 185,672.76
  5. Step 5: Solve for x
    x = 185,672.76/485.65
  6. Step 6: Final answer
    x = 382.32

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.