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Finding the Fourth Proportional to 645.15, 890.31 and 350.42

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Solution

The fourth proportional to 645.15, 890.31 and 350.42 is: 483.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.15 : 890.31 = 350.42 : x
  2. Step 2: Convert to fraction form
    645.15/890.31 = 350.42/x
  3. Step 3: Cross multiply
    645.15x = 890.31 × 350.42
  4. Step 4: Simplify right side
    645.15x = 311,982.43
  5. Step 5: Solve for x
    x = 311,982.43/645.15
  6. Step 6: Final answer
    x = 483.58

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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.