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Finding the Fourth Proportional to 500.80, 690.28 and 390.08

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Solution

The fourth proportional to 500.80, 690.28 and 390.08 is: 537.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    500.80 : 690.28 = 390.08 : x
  2. Step 2: Convert to fraction form
    500.80/690.28 = 390.08/x
  3. Step 3: Cross multiply
    500.80x = 690.28 × 390.08
  4. Step 4: Simplify right side
    500.80x = 269,265.17
  5. Step 5: Solve for x
    x = 269,265.17/500.80
  6. Step 6: Final answer
    x = 537.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.