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Finding the Fourth Proportional to 811.23, 1,216.74 and 485.82

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Solution

The fourth proportional to 811.23, 1,216.74 and 485.82 is: 728.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.23 : 1,216.74 = 485.82 : x
  2. Step 2: Convert to fraction form
    811.23/1,216.74 = 485.82/x
  3. Step 3: Cross multiply
    811.23x = 1,216.74 × 485.82
  4. Step 4: Simplify right side
    811.23x = 591,116.63
  5. Step 5: Solve for x
    x = 591,116.63/811.23
  6. Step 6: Final answer
    x = 728.67

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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.