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Finding the Fourth Proportional to 390.78, 586.53 and 275.67

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Solution

The fourth proportional to 390.78, 586.53 and 275.67 is: 413.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.78 : 586.53 = 275.67 : x
  2. Step 2: Convert to fraction form
    390.78/586.53 = 275.67/x
  3. Step 3: Cross multiply
    390.78x = 586.53 × 275.67
  4. Step 4: Simplify right side
    390.78x = 161,688.73
  5. Step 5: Solve for x
    x = 161,688.73/390.78
  6. Step 6: Final answer
    x = 413.76

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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.