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Finding the Fourth Proportional to 659.16, 987.75 and 639.45

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Solution

The fourth proportional to 659.16, 987.75 and 639.45 is: 958.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.16 : 987.75 = 639.45 : x
  2. Step 2: Convert to fraction form
    659.16/987.75 = 639.45/x
  3. Step 3: Cross multiply
    659.16x = 987.75 × 639.45
  4. Step 4: Simplify right side
    659.16x = 631,616.74
  5. Step 5: Solve for x
    x = 631,616.74/659.16
  6. Step 6: Final answer
    x = 958.21

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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.