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Finding the Fourth Proportional to 306.90, 423.90 and 289.08

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Solution

The fourth proportional to 306.90, 423.90 and 289.08 is: 399.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.90 : 423.90 = 289.08 : x
  2. Step 2: Convert to fraction form
    306.90/423.90 = 289.08/x
  3. Step 3: Cross multiply
    306.90x = 423.90 × 289.08
  4. Step 4: Simplify right side
    306.90x = 122,541.01
  5. Step 5: Solve for x
    x = 122,541.01/306.90
  6. Step 6: Final answer
    x = 399.29

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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.