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Finding the Fourth Proportional to 992.30, 1,369.36 and 643.58

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Solution

The fourth proportional to 992.30, 1,369.36 and 643.58 is: 888.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    992.30 : 1,369.36 = 643.58 : x
  2. Step 2: Convert to fraction form
    992.30/1,369.36 = 643.58/x
  3. Step 3: Cross multiply
    992.30x = 1,369.36 × 643.58
  4. Step 4: Simplify right side
    992.30x = 881,292.71
  5. Step 5: Solve for x
    x = 881,292.71/992.30
  6. Step 6: Final answer
    x = 888.13

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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.