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Finding the Fourth Proportional to 275.51, 379.80 and 209.90

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Solution

The fourth proportional to 275.51, 379.80 and 209.90 is: 289.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    275.51 : 379.80 = 209.90 : x
  2. Step 2: Convert to fraction form
    275.51/379.80 = 209.90/x
  3. Step 3: Cross multiply
    275.51x = 379.80 × 209.90
  4. Step 4: Simplify right side
    275.51x = 79,718.12
  5. Step 5: Solve for x
    x = 79,718.12/275.51
  6. Step 6: Final answer
    x = 289.35

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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.