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Finding the Fourth Proportional to 491.90, 678.66 and 317.36

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Solution

The fourth proportional to 491.90, 678.66 and 317.36 is: 437.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.90 : 678.66 = 317.36 : x
  2. Step 2: Convert to fraction form
    491.90/678.66 = 317.36/x
  3. Step 3: Cross multiply
    491.90x = 678.66 × 317.36
  4. Step 4: Simplify right side
    491.90x = 215,379.54
  5. Step 5: Solve for x
    x = 215,379.54/491.90
  6. Step 6: Final answer
    x = 437.85

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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.