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Finding the Fourth Proportional to 620.21, 855.89 and 340.45

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Solution

The fourth proportional to 620.21, 855.89 and 340.45 is: 469.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.21 : 855.89 = 340.45 : x
  2. Step 2: Convert to fraction form
    620.21/855.89 = 340.45/x
  3. Step 3: Cross multiply
    620.21x = 855.89 × 340.45
  4. Step 4: Simplify right side
    620.21x = 291,391.40
  5. Step 5: Solve for x
    x = 291,391.40/620.21
  6. Step 6: Final answer
    x = 469.82

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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.