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Finding the Fourth Proportional to 491.71, 678.47 and 317.29

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Solution

The fourth proportional to 491.71, 678.47 and 317.29 is: 437.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.71 : 678.47 = 317.29 : x
  2. Step 2: Convert to fraction form
    491.71/678.47 = 317.29/x
  3. Step 3: Cross multiply
    491.71x = 678.47 × 317.29
  4. Step 4: Simplify right side
    491.71x = 215,270.16
  5. Step 5: Solve for x
    x = 215,270.16/491.71
  6. Step 6: Final answer
    x = 437.80

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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.