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Finding the Fourth Proportional to 688.42, 948.27 and 643.06

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Solution

The fourth proportional to 688.42, 948.27 and 643.06 is: 885.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.42 : 948.27 = 643.06 : x
  2. Step 2: Convert to fraction form
    688.42/948.27 = 643.06/x
  3. Step 3: Cross multiply
    688.42x = 948.27 × 643.06
  4. Step 4: Simplify right side
    688.42x = 609,794.51
  5. Step 5: Solve for x
    x = 609,794.51/688.42
  6. Step 6: Final answer
    x = 885.79

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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.