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Finding the Fourth Proportional to 659.77, 989.64 and 172.80

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Solution

The fourth proportional to 659.77, 989.64 and 172.80 is: 259.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.77 : 989.64 = 172.80 : x
  2. Step 2: Convert to fraction form
    659.77/989.64 = 172.80/x
  3. Step 3: Cross multiply
    659.77x = 989.64 × 172.80
  4. Step 4: Simplify right side
    659.77x = 171,009.79
  5. Step 5: Solve for x
    x = 171,009.79/659.77
  6. Step 6: Final answer
    x = 259.20

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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.