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Finding the Fourth Proportional to 421.40, 581.74 and 289.33

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Solution

The fourth proportional to 421.40, 581.74 and 289.33 is: 399.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.40 : 581.74 = 289.33 : x
  2. Step 2: Convert to fraction form
    421.40/581.74 = 289.33/x
  3. Step 3: Cross multiply
    421.40x = 581.74 × 289.33
  4. Step 4: Simplify right side
    421.40x = 168,312.66
  5. Step 5: Solve for x
    x = 168,312.66/421.40
  6. Step 6: Final answer
    x = 399.41

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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.