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Finding the Fourth Proportional to 211.54, 317.45 and 139.45

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Solution

The fourth proportional to 211.54, 317.45 and 139.45 is: 209.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.54 : 317.45 = 139.45 : x
  2. Step 2: Convert to fraction form
    211.54/317.45 = 139.45/x
  3. Step 3: Cross multiply
    211.54x = 317.45 × 139.45
  4. Step 4: Simplify right side
    211.54x = 44,267.71
  5. Step 5: Solve for x
    x = 44,267.71/211.54
  6. Step 6: Final answer
    x = 209.26

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.