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Finding the Fourth Proportional to 814.20, 1,218.93 and 639.24

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Solution

The fourth proportional to 814.20, 1,218.93 and 639.24 is: 957.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.20 : 1,218.93 = 639.24 : x
  2. Step 2: Convert to fraction form
    814.20/1,218.93 = 639.24/x
  3. Step 3: Cross multiply
    814.20x = 1,218.93 × 639.24
  4. Step 4: Simplify right side
    814.20x = 779,188.81
  5. Step 5: Solve for x
    x = 779,188.81/814.20
  6. Step 6: Final answer
    x = 957.00

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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.