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Finding the Fourth Proportional to 690.21, 1,035.36 and 203.40

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Solution

The fourth proportional to 690.21, 1,035.36 and 203.40 is: 305.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.21 : 1,035.36 = 203.40 : x
  2. Step 2: Convert to fraction form
    690.21/1,035.36 = 203.40/x
  3. Step 3: Cross multiply
    690.21x = 1,035.36 × 203.40
  4. Step 4: Simplify right side
    690.21x = 210,592.22
  5. Step 5: Solve for x
    x = 210,592.22/690.21
  6. Step 6: Final answer
    x = 305.11

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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.