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Finding the Fourth Proportional to 643.45, 965.43 and 383.57

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Solution

The fourth proportional to 643.45, 965.43 and 383.57 is: 575.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.45 : 965.43 = 383.57 : x
  2. Step 2: Convert to fraction form
    643.45/965.43 = 383.57/x
  3. Step 3: Cross multiply
    643.45x = 965.43 × 383.57
  4. Step 4: Simplify right side
    643.45x = 370,309.99
  5. Step 5: Solve for x
    x = 370,309.99/643.45
  6. Step 6: Final answer
    x = 575.51

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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.