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Finding the Fourth Proportional to 811.72, 1,217.58 and 619.48

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Solution

The fourth proportional to 811.72, 1,217.58 and 619.48 is: 929.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.72 : 1,217.58 = 619.48 : x
  2. Step 2: Convert to fraction form
    811.72/1,217.58 = 619.48/x
  3. Step 3: Cross multiply
    811.72x = 1,217.58 × 619.48
  4. Step 4: Simplify right side
    811.72x = 754,266.46
  5. Step 5: Solve for x
    x = 754,266.46/811.72
  6. Step 6: Final answer
    x = 929.22

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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.