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Finding the Fourth Proportional to 659.95, 989.43 and 399.89

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Solution

The fourth proportional to 659.95, 989.43 and 399.89 is: 599.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.95 : 989.43 = 399.89 : x
  2. Step 2: Convert to fraction form
    659.95/989.43 = 399.89/x
  3. Step 3: Cross multiply
    659.95x = 989.43 × 399.89
  4. Step 4: Simplify right side
    659.95x = 395,663.16
  5. Step 5: Solve for x
    x = 395,663.16/659.95
  6. Step 6: Final answer
    x = 599.54

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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.