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Finding the Fourth Proportional to 645.80, 890.70 and 446.20

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Solution

The fourth proportional to 645.80, 890.70 and 446.20 is: 615.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.80 : 890.70 = 446.20 : x
  2. Step 2: Convert to fraction form
    645.80/890.70 = 446.20/x
  3. Step 3: Cross multiply
    645.80x = 890.70 × 446.20
  4. Step 4: Simplify right side
    645.80x = 397,430.34
  5. Step 5: Solve for x
    x = 397,430.34/645.80
  6. Step 6: Final answer
    x = 615.41

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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.