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Finding the Fourth Proportional to 808.65, 1,116.47 and 621.80

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Solution

The fourth proportional to 808.65, 1,116.47 and 621.80 is: 858.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.65 : 1,116.47 = 621.80 : x
  2. Step 2: Convert to fraction form
    808.65/1,116.47 = 621.80/x
  3. Step 3: Cross multiply
    808.65x = 1,116.47 × 621.80
  4. Step 4: Simplify right side
    808.65x = 694,212.35
  5. Step 5: Solve for x
    x = 694,212.35/808.65
  6. Step 6: Final answer
    x = 858.48

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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.