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Finding the Fourth Proportional to 678.75, 936.80 and 402.75

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Solution

The fourth proportional to 678.75, 936.80 and 402.75 is: 555.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.75 : 936.80 = 402.75 : x
  2. Step 2: Convert to fraction form
    678.75/936.80 = 402.75/x
  3. Step 3: Cross multiply
    678.75x = 936.80 × 402.75
  4. Step 4: Simplify right side
    678.75x = 377,294.19
  5. Step 5: Solve for x
    x = 377,294.19/678.75
  6. Step 6: Final answer
    x = 555.87

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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.