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Finding the Fourth Proportional to 309.71, 426.93 and 289.01

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Solution

The fourth proportional to 309.71, 426.93 and 289.01 is: 398.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.71 : 426.93 = 289.01 : x
  2. Step 2: Convert to fraction form
    309.71/426.93 = 289.01/x
  3. Step 3: Cross multiply
    309.71x = 426.93 × 289.01
  4. Step 4: Simplify right side
    309.71x = 123,387.04
  5. Step 5: Solve for x
    x = 123,387.04/309.71
  6. Step 6: Final answer
    x = 398.40

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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.