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Finding the Fourth Proportional to 678.99, 1,018.31 and 288.98

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Solution

The fourth proportional to 678.99, 1,018.31 and 288.98 is: 433.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.99 : 1,018.31 = 288.98 : x
  2. Step 2: Convert to fraction form
    678.99/1,018.31 = 288.98/x
  3. Step 3: Cross multiply
    678.99x = 1,018.31 × 288.98
  4. Step 4: Simplify right side
    678.99x = 294,264.69
  5. Step 5: Solve for x
    x = 294,264.69/678.99
  6. Step 6: Final answer
    x = 433.39

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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.