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Finding the Fourth Proportional to 718.72, 990.40 and 511.36

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Solution

The fourth proportional to 718.72, 990.40 and 511.36 is: 704.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.72 : 990.40 = 511.36 : x
  2. Step 2: Convert to fraction form
    718.72/990.40 = 511.36/x
  3. Step 3: Cross multiply
    718.72x = 990.40 × 511.36
  4. Step 4: Simplify right side
    718.72x = 506,450.94
  5. Step 5: Solve for x
    x = 506,450.94/718.72
  6. Step 6: Final answer
    x = 704.66

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.