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Finding the Fourth Proportional to 690.50, 1,035.20 and 325.20

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Solution

The fourth proportional to 690.50, 1,035.20 and 325.20 is: 487.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.50 : 1,035.20 = 325.20 : x
  2. Step 2: Convert to fraction form
    690.50/1,035.20 = 325.20/x
  3. Step 3: Cross multiply
    690.50x = 1,035.20 × 325.20
  4. Step 4: Simplify right side
    690.50x = 336,647.04
  5. Step 5: Solve for x
    x = 336,647.04/690.50
  6. Step 6: Final answer
    x = 487.54

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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.