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Finding the Fourth Proportional to 491.38, 678.18 and 317.23

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Solution

The fourth proportional to 491.38, 678.18 and 317.23 is: 437.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.38 : 678.18 = 317.23 : x
  2. Step 2: Convert to fraction form
    491.38/678.18 = 317.23/x
  3. Step 3: Cross multiply
    491.38x = 678.18 × 317.23
  4. Step 4: Simplify right side
    491.38x = 215,139.04
  5. Step 5: Solve for x
    x = 215,139.04/491.38
  6. Step 6: Final answer
    x = 437.83

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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.