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Finding the Fourth Proportional to 690.42, 1,035.62 and 279.55

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Solution

The fourth proportional to 690.42, 1,035.62 and 279.55 is: 419.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.42 : 1,035.62 = 279.55 : x
  2. Step 2: Convert to fraction form
    690.42/1,035.62 = 279.55/x
  3. Step 3: Cross multiply
    690.42x = 1,035.62 × 279.55
  4. Step 4: Simplify right side
    690.42x = 289,507.57
  5. Step 5: Solve for x
    x = 289,507.57/690.42
  6. Step 6: Final answer
    x = 419.32

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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.