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Finding the Fourth Proportional to 620, 856 and 488.80

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Solution

The fourth proportional to 620, 856 and 488.80 is: 674.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    620 : 856 = 488.80 : x
  2. Step 2: Convert to fraction form
    620/856 = 488.80/x
  3. Step 3: Cross multiply
    620x = 856 × 488.80
  4. Step 4: Simplify right side
    620x = 418,412.80
  5. Step 5: Solve for x
    x = 418,412.80/620
  6. Step 6: Final answer
    x = 674.86

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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.