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Finding the Fourth Proportional to 491.80, 679 and 305.49

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Solution

The fourth proportional to 491.80, 679 and 305.49 is: 421.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.80 : 679 = 305.49 : x
  2. Step 2: Convert to fraction form
    491.80/679 = 305.49/x
  3. Step 3: Cross multiply
    491.80x = 679 × 305.49
  4. Step 4: Simplify right side
    491.80x = 207,427.71
  5. Step 5: Solve for x
    x = 207,427.71/491.80
  6. Step 6: Final answer
    x = 421.77

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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.