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Finding the Fourth Proportional to 620.30, 855.99 and 354.75

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Solution

The fourth proportional to 620.30, 855.99 and 354.75 is: 489.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.30 : 855.99 = 354.75 : x
  2. Step 2: Convert to fraction form
    620.30/855.99 = 354.75/x
  3. Step 3: Cross multiply
    620.30x = 855.99 × 354.75
  4. Step 4: Simplify right side
    620.30x = 303,662.45
  5. Step 5: Solve for x
    x = 303,662.45/620.30
  6. Step 6: Final answer
    x = 489.54

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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.