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Finding the Fourth Proportional to 690, 1,035 and 300.39

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Solution

The fourth proportional to 690, 1,035 and 300.39 is: 450.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    690 : 1,035 = 300.39 : x
  2. Step 2: Convert to fraction form
    690/1,035 = 300.39/x
  3. Step 3: Cross multiply
    690x = 1,035 × 300.39
  4. Step 4: Simplify right side
    690x = 310,903.65
  5. Step 5: Solve for x
    x = 310,903.65/690
  6. Step 6: Final answer
    x = 450.59

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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.