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Finding the Fourth Proportional to 678.23, 1,016.40 and 381.47

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Solution

The fourth proportional to 678.23, 1,016.40 and 381.47 is: 571.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.23 : 1,016.40 = 381.47 : x
  2. Step 2: Convert to fraction form
    678.23/1,016.40 = 381.47/x
  3. Step 3: Cross multiply
    678.23x = 1,016.40 × 381.47
  4. Step 4: Simplify right side
    678.23x = 387,726.03
  5. Step 5: Solve for x
    x = 387,726.03/678.23
  6. Step 6: Final answer
    x = 571.67

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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.