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Finding the Fourth Proportional to 855.19, 1,180.21 and 644.99

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Solution

The fourth proportional to 855.19, 1,180.21 and 644.99 is: 890.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.19 : 1,180.21 = 644.99 : x
  2. Step 2: Convert to fraction form
    855.19/1,180.21 = 644.99/x
  3. Step 3: Cross multiply
    855.19x = 1,180.21 × 644.99
  4. Step 4: Simplify right side
    855.19x = 761,223.65
  5. Step 5: Solve for x
    x = 761,223.65/855.19
  6. Step 6: Final answer
    x = 890.13

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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.