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Finding the Fourth Proportional to 520.80, 718.65 and 299.78

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Solution

The fourth proportional to 520.80, 718.65 and 299.78 is: 413.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.80 : 718.65 = 299.78 : x
  2. Step 2: Convert to fraction form
    520.80/718.65 = 299.78/x
  3. Step 3: Cross multiply
    520.80x = 718.65 × 299.78
  4. Step 4: Simplify right side
    520.80x = 215,437.19
  5. Step 5: Solve for x
    x = 215,437.19/520.80
  6. Step 6: Final answer
    x = 413.67

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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.