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Finding the Fourth Proportional to 289.55, 399.40 and 210.77

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Solution

The fourth proportional to 289.55, 399.40 and 210.77 is: 290.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.55 : 399.40 = 210.77 : x
  2. Step 2: Convert to fraction form
    289.55/399.40 = 210.77/x
  3. Step 3: Cross multiply
    289.55x = 399.40 × 210.77
  4. Step 4: Simplify right side
    289.55x = 84,182.80
  5. Step 5: Solve for x
    x = 84,182.80/289.55
  6. Step 6: Final answer
    x = 290.73

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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.