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Finding the Fourth Proportional to 491.80, 678.68 and 317.08

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Solution

The fourth proportional to 491.80, 678.68 and 317.08 is: 437.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.80 : 678.68 = 317.08 : x
  2. Step 2: Convert to fraction form
    491.80/678.68 = 317.08/x
  3. Step 3: Cross multiply
    491.80x = 678.68 × 317.08
  4. Step 4: Simplify right side
    491.80x = 215,195.85
  5. Step 5: Solve for x
    x = 215,195.85/491.80
  6. Step 6: Final answer
    x = 437.57

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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.