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Finding the Fourth Proportional to 890.09, 1,228.32 and 491.75

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Solution

The fourth proportional to 890.09, 1,228.32 and 491.75 is: 678.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.09 : 1,228.32 = 491.75 : x
  2. Step 2: Convert to fraction form
    890.09/1,228.32 = 491.75/x
  3. Step 3: Cross multiply
    890.09x = 1,228.32 × 491.75
  4. Step 4: Simplify right side
    890.09x = 604,020.22
  5. Step 5: Solve for x
    x = 604,020.22/890.09
  6. Step 6: Final answer
    x = 678.61

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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.