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Finding the Fourth Proportional to 645.24, 890.64 and 379.80

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Solution

The fourth proportional to 645.24, 890.64 and 379.80 is: 524.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.24 : 890.64 = 379.80 : x
  2. Step 2: Convert to fraction form
    645.24/890.64 = 379.80/x
  3. Step 3: Cross multiply
    645.24x = 890.64 × 379.80
  4. Step 4: Simplify right side
    645.24x = 338,265.07
  5. Step 5: Solve for x
    x = 338,265.07/645.24
  6. Step 6: Final answer
    x = 524.25

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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.