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Finding the Fourth Proportional to 643.12, 965.09 and 412.18

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Solution

The fourth proportional to 643.12, 965.09 and 412.18 is: 618.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.12 : 965.09 = 412.18 : x
  2. Step 2: Convert to fraction form
    643.12/965.09 = 412.18/x
  3. Step 3: Cross multiply
    643.12x = 965.09 × 412.18
  4. Step 4: Simplify right side
    643.12x = 397,790.80
  5. Step 5: Solve for x
    x = 397,790.80/643.12
  6. Step 6: Final answer
    x = 618.53

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1.5x scale

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.