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Finding the Fourth Proportional to 690.25, 1,035.27 and 279.28

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Solution

The fourth proportional to 690.25, 1,035.27 and 279.28 is: 418.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.25 : 1,035.27 = 279.28 : x
  2. Step 2: Convert to fraction form
    690.25/1,035.27 = 279.28/x
  3. Step 3: Cross multiply
    690.25x = 1,035.27 × 279.28
  4. Step 4: Simplify right side
    690.25x = 289,128.81
  5. Step 5: Solve for x
    x = 289,128.81/690.25
  6. Step 6: Final answer
    x = 418.88

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.