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Finding the Fourth Proportional to 317.79, 438.55 and 186.80

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Solution

The fourth proportional to 317.79, 438.55 and 186.80 is: 257.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    317.79 : 438.55 = 186.80 : x
  2. Step 2: Convert to fraction form
    317.79/438.55 = 186.80/x
  3. Step 3: Cross multiply
    317.79x = 438.55 × 186.80
  4. Step 4: Simplify right side
    317.79x = 81,920.21
  5. Step 5: Solve for x
    x = 81,920.21/317.79
  6. Step 6: Final answer
    x = 257.78

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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.