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Finding the Fourth Proportional to 810.54, 1,215.84 and 485.19

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Solution

The fourth proportional to 810.54, 1,215.84 and 485.19 is: 727.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.54 : 1,215.84 = 485.19 : x
  2. Step 2: Convert to fraction form
    810.54/1,215.84 = 485.19/x
  3. Step 3: Cross multiply
    810.54x = 1,215.84 × 485.19
  4. Step 4: Simplify right side
    810.54x = 589,913.41
  5. Step 5: Solve for x
    x = 589,913.41/810.54
  6. Step 6: Final answer
    x = 727.80

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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.