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Finding the Fourth Proportional to 645.80, 890.88 and 409.34

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Solution

The fourth proportional to 645.80, 890.88 and 409.34 is: 564.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.80 : 890.88 = 409.34 : x
  2. Step 2: Convert to fraction form
    645.80/890.88 = 409.34/x
  3. Step 3: Cross multiply
    645.80x = 890.88 × 409.34
  4. Step 4: Simplify right side
    645.80x = 364,672.82
  5. Step 5: Solve for x
    x = 364,672.82/645.80
  6. Step 6: Final answer
    x = 564.68

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1.5x scale

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.