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Finding the Fourth Proportional to 645.18, 890.38 and 379.70

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Solution

The fourth proportional to 645.18, 890.38 and 379.70 is: 524.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.18 : 890.38 = 379.70 : x
  2. Step 2: Convert to fraction form
    645.18/890.38 = 379.70/x
  3. Step 3: Cross multiply
    645.18x = 890.38 × 379.70
  4. Step 4: Simplify right side
    645.18x = 338,077.29
  5. Step 5: Solve for x
    x = 338,077.29/645.18
  6. Step 6: Final answer
    x = 524.00

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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.