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Finding the Fourth Proportional to 678.18, 1,017.26 and 239.45

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Solution

The fourth proportional to 678.18, 1,017.26 and 239.45 is: 359.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.18 : 1,017.26 = 239.45 : x
  2. Step 2: Convert to fraction form
    678.18/1,017.26 = 239.45/x
  3. Step 3: Cross multiply
    678.18x = 1,017.26 × 239.45
  4. Step 4: Simplify right side
    678.18x = 243,577.82
  5. Step 5: Solve for x
    x = 243,577.82/678.18
  6. Step 6: Final answer
    x = 359.16

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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.