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Finding the Fourth Proportional to 777.90, 1,072.47 and 628.36

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Solution

The fourth proportional to 777.90, 1,072.47 and 628.36 is: 866.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    777.90 : 1,072.47 = 628.36 : x
  2. Step 2: Convert to fraction form
    777.90/1,072.47 = 628.36/x
  3. Step 3: Cross multiply
    777.90x = 1,072.47 × 628.36
  4. Step 4: Simplify right side
    777.90x = 673,895.99
  5. Step 5: Solve for x
    x = 673,895.99/777.90
  6. Step 6: Final answer
    x = 866.30

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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.